<!-- If the browser does not support frames put the first topic content here --> <div class="Section1"> <p class="MsoNormal" align="center" style='text-align:center'> <b><span style='font-size:18.0pt'>L'héritage</span></b></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <h1><a name="node0" id="node0"></a><span style= 'text-decoration:none'>1.<span style= 'font:7.0pt "Times New Roman"'> </span></span> INTRODUCTION</h1> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="Adresse"><span style= 'layout-grid-mode:both'>Exemple :</span></p> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'> <b><u><span style='font-size:12.0pt'><span style= 'text-decoration:none'> </span></span></u></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'>classe Véhicule //n’importe quel objet roulant</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>privé:</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'>noveh : entier</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> couleur : chaîne de caractères</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'>poids : réel //poids du véhicule </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>public:</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'>PROCEDURE initialiser (données : n : entier, c : chaîne de caractères, p : réel) </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> DEBUT</span></p> <p class="MsoNormal" style= 'text-indent:1.0cm;border:none;padding:0cm'><span style= 'font-size:12.0pt'> noveh</span> <span style= 'font-size: 12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'>n</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> couleur</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'>c</span></p> <p class="MsoNormal" style= 'text-indent:1.0cm;border:none;padding:0cm'><span style= 'font-size:12.0pt'> poids</span> <span style= 'font-size: 12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'>p</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'>FIN</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'>FONCTION donnercouleur() : chaîne de caractères</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> DEBUT</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> Retourner couleur</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> FIN</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'>FONCTION donnerpoids() : réel</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:12.0pt'>DEBUT</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> Retourner poids</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> FIN</span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'>Fclasse</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'>classe Voiture : hérite de Véhicule //classe pour les voitures</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'>Fclasse</span></b></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Cette déclaration stipule que la classe "Voiture" <b>dérive</b> de "Véhicule", c’est à dire qu’elle en possède toutes les caractéristiques. En clair, une" Voiture " est un "Véhicule". La classe "Véhicule" est dite "<b>classe de base</b>", " Voiture " est appelée une "<b>classe dérivée</b> de Véhicule".</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Un objet de type « Voiture » possédera donc les données membres noveh, couleur, poids et toutes les méthodes de « Véhicule » (sauf les constructeurs (cf. codage en Java)) :</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>procédure initialiser(données: n : entier, c : chaîne de caractères, p : réel) </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>fonction donnercouleur() : chaîne de caractères </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>fonction donnerpoids() : réel</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <h1><a name="node1" id="node1"></a><span style= 'text-decoration:none'>2.<span style= 'font:7.0pt "Times New Roman"'> </span></span> UTILISATION DES MEMBRES « HERITES »</h1> <p class="MsoNormal"> </p> <p class="MsoNormal"><span style='font-size:12.0pt'>Nous venons de voir que la classe dérivée "hérite" des membres définis dans la classe de base (données et méthodes).</span></p> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 1.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>Programme Test1</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>DEBUT</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>VAR <b>voit1 : Voiture</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> pds : réel</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> //initialisation de voit1</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> <b>voit1.initialiser (1, « rouge », 1500)</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> <s>Afficher « Couleur : », <b>voit1.couleur </b></s> <b>//interdit tout comme avec un</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> //objet de type Véhicule</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> pds</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'><b>voit1.donnerpoids()</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> …</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>FIN</span></p> </div> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <h6><a name="node2" id="node2"></a>Les membres publics méthodes ou données de la classe de base sont utilisables avec un objet de la classe dérivée tout comme avec un objet de la classe de base.</h6> <p class="MsoNormal"> </p> <p class="MsoNormal"><span style='font-size:12.0pt'>Remarque : en Java, l'héritage multiple n'existe pas, seul l'héritage simple est possible, c'est à dire qu'une classe ne peut être dérivée de plusieurs classes.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"> </p> <h1><a name="node3" id="node3"></a><span style= 'text-decoration:none'>3.<span style= 'font:7.0pt "Times New Roman"'> </span></span> SPECIALISATION</h1> <p class="MsoNormal"> </p> <p class="MsoNormal"><span style='font-size:12.0pt'>Pour le moment, la classe "Voiture" est identique à la classe " Véhicule" et ne présente donc aucun intérêt. La spécialisation consiste à ajouter des méthodes ou des données à la classe dérivée (on dit que l’on spécialise la classe de base).</span></p> <p class="Adresse"><span style= 'layout-grid-mode:both'> </span></p> <p class="Adresse"><span style= 'layout-grid-mode:both'>Exemple :</span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'>classe Voiture : hérite de Véhicule</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>privé :</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> nbpassagers :entier</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> métallisé : booléen</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>public :</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> PROCEDURE initialiser(données : n : entier, c : chaîne de caractères, p : réel, gens : entier, metal : booléen)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> DEBUT</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> initialiser(n, c, p)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> nbpassagers</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'>gens</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> métallisé</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'>métal</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> FIN</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> FONCTION donnerpassagers() : entier</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> DEBUT</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> Retourner nbpassagers</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> FIN</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> FONCTION donnercouleur() : chaîne de caractères</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> DEBUT</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> SI métallisé</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> ALORS</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> texte</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'>" métallisé"</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> SINON</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> texte</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'>" mat"</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> FSI</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> Retourner Véhicule::donnercouleur() + texte // Il est impossible de retourner</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> // couleur + texte FIN</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'>Fclasse</span></b></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Chaque « Voiture » possède 5 membres "données" : noveh, couleur, poids, nbpassagers, métallisé et toutes les méthodes des 2 classes :</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>procédure initialiser(données : n : entier, c : chaîne de caractères, p : réel) //initialisation de no, couleur et poids </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>procédure initialiser(données : n : entier, c : chaîne de caractères, gens :entier, métal : booléen ) //initialisation de toutes les données </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>fonction donnercouleur() : chaîne de caractères //fonction de la classe Véhicule</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>fonction donnercouleur() : chaîne de caractères //fonction de la classe Voiture</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>fonction donnerpoids() : réel</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>fonction donnerpassagers() : entier</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Il est donc possible d’attribuer le même nom à des membres de la classe héritée et à des membres de la classe de base.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 1.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>Programme Test2</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>DEBUT</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>VAR <b>véh1, véh2 : Véhicule</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> <b>voit1, voit2 : Voiture</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>pds : réel</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> couleur : chaîne de caractères</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> nbpas : entier</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> <b>voit1.initialiser (1, "bleu", 1000) // Appel à initialiser de Véhicule</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> voit2.initialiser (2, "rouge", 1500, 7, Vrai) // Appel à initialiser de Voiture</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> véh1.initialiser (1, "vert", 800) // Appel à initialiser de Véhicule</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> <s>véh2.initialiser (2, "jaune", 900, 7, Vrai)</s> // Erreur</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> pds</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size:12.0pt'><b>voit1.donnerpoids() // Appel à donnerpoids de Véhicule</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>pds</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size: 12.0pt'><b>voit2.donnerpoids() // Appel à donnerpoids de Véhicule</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>pds</span> <span style= 'font-size:12.0pt;font-family:Wingdings'>ß</span> <span style= 'font-size: 12.0pt'><b>véh1.donnerpoids() // Appel à donnerpoids de Véhicule</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>couleur</span> <span style= 'font-size:12.0pt;font-family: Wingdings'>ß</span> <span style= 'font-size:12.0pt'><b>voit1.donnercouleur() // Appel à donnercouleur de Voiture</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>couleur</span> <span style= 'font-size:12.0pt;font-family: Wingdings'>ß</span> <span style= 'font-size:12.0pt'><b>voit2.donnercouleur() // Appel à donnercouleur de Voiture</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>couleur</span> <span style= 'font-size:12.0pt;font-family: Wingdings'>ß</span> <span style= 'font-size:12.0pt'><b>véh1.donnercouleur() // Appel à donnercouleur de Véhicule</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>nbpas</span> <span style= 'font-size:12.0pt;font-family: Wingdings'>ß</span> <span style= 'font-size:12.0pt'><b>voit1.donnerpassagers() // Appel à donnerpassagers</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> // Peut rendre n'importe quoi car non</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> // initialisé (c'est ce que l'on considère en</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> // pseudo-code)</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <span style='font-size:12.0pt'>nbpas</span> <span style= 'font-size:12.0pt;font-family: Wingdings'>ß</span> <span style= 'font-size:12.0pt'><b>voit2.donnerpassagers() // Appel à donnerpassagers</b></span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> // Place 7 dans nbpas</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b> <s><span style='font-size:12.0pt'>nbpas</span></s> <s><span style= 'font-size:12.0pt; font-family:Wingdings'>ß</span></s> <s><span style= 'font-size:12.0pt'><b>véh1.donnerpassagers()</b></span></s><b><span style='font-size:12.0pt'> // Erreur</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> …</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'>FIN</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Remarque : il est impossible d'appliquer une méthode ou d'utiliser une donnée de la classe dérivée avec un objet de la classe de base (on verra qu’on peut le faire en Java avec une référence de la classe de base si la référence désigne un objet de la classe dérivée).</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Règles pour les méthodes publiques :</span></u></b></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>- Si la méthode n’existe pas dans la classe dérivée, il y a appel de la méthode de la classe de base.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Exemple : ………………………………..</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>- S'il y a une méthode de même nom mais avec une signature différente, l’appel se fait suivant la concordance entre les paramètres effectifs et les paramètres formels. On parle de <b>surcharge</b> comme c'est le cas à l'intérieur d'une même classe.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Exemple : ……………………………..</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>- Si la signature est la même, on dit alors que la méthode est <b>redéfinie</b> dans la classe dérivéeou qu’elle <b>outrepasse</b> la méthode de la classe de base. La méthode de la classe de l’objet d’appel s’applique, on dit qu’elle <b>cache</b> la méthode de la classe de base. On dit également qu'il y a <b>masquage</b> de la méthode de la classe de base.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Exemple : ……………………………..</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Pour appeler explicitement la méthode de la classe de base (ceci sera possible uniquement à l'intérieur de la classe héritée et non dans les autres programmes) avec un objet de la classe dérivée, il faudra indiquer NomClasseBase::NomMéthode().</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Exemple : ……………………………..</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="DefinitionTerm"><span style='layout-grid-mode:both'>C’est évidemment la méthode de la classe dérivée qui est considérée quand la méthode n’existe pas dans la classe de base (dans ce cas, Java ne regarde même pas dans la classe de base).</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Exemple : ……………………………..</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Règles pour les données publiques :</span></u></b></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="DefinitionTerm" style='margin-left:0cm;text-indent:0cm'> <span style='layout-grid-mode:both'>-<span style= 'font:7.0pt "Times New Roman"'> </span></span> <span style='layout-grid-mode:both'>Si la donnée n'existe pas dans la classe dérivée, c'est la donnée de la classe de base qui est considérée.</span></p> <p class="DefinitionTerm" style='margin-left:0cm;text-indent:0cm'> <span style='layout-grid-mode:both'>-<span style= 'font:7.0pt "Times New Roman"'> </span></span> <span style='layout-grid-mode:both'>Si la donnée est redéfinie, c'est la donnée de la classe de l'objet d'appel qui est considérée à moins d'indiquer NomClasseBase::NomDonnée.</span></p> <p class="DefinitionTerm" style='margin-left:0cm;text-indent:0cm'> <span style='layout-grid-mode:both'>-<span style= 'font:7.0pt "Times New Roman"'> </span></span> <span style='layout-grid-mode:both'>C’est évidemment la donnée de la classe dérivée qui est considérée quand la donnée n’existe pas dans la classe de base (dans ce cas, Java ne regarde même pas dans la classe de base).</span></p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Règles pour les données et méthodes privées</span></u></b></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Les membres privés de la classe de base sont inaccessibles à l'intérieur des méthodes de la classe dérivée comme ils le sont de façon générale à l'extérieur de la classe de base.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Par exemple, il ne sera pas possible de désigner couleur dans une méthode de la classe Voiture car c’est un membre <b>privé</b> de « Véhicule » ; il faudra donc utiliser la fonction donnercouleur de la classe « Véhicule »pour récupérer la valeur de couleur.</span></p> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Remarque :</span></u></b></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Toutes les règles citées précédemment sont également valables pour les méthodes et données statiques.</span></p> <p class="DefinitionTerm"><span style= 'layout-grid-mode:both'> </span></p> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <h1><a name="node4" id="node4"></a><span style= 'text-decoration:none'>4.<span style= 'font:7.0pt "Times New Roman"'> </span></span> EXERCICE D'APPLICATION</h1> <p class="MsoNormal"><u><span style='font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></p> <p class="MsoNormal"><i><span style='font-size:12.0pt'>Considérons les déclarations :</span></i></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-family:"Courier New"'>CLASSE A</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> privé</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> x, y : entier</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> public :</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> PROCEDURE initial (données : i, j : entier)</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> PROCEDURE affiche ()</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> PROCEDURE affiche_x ()</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'>FCLASSE</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> </span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> </span></p> <p class="MsoNormal"><span style='font-family:"Courier New"'>CLASSE B : hérite de A</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> privé</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> x, z : entier /* redéfinition de x */</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> public</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> PROCEDURE initial (données : i, j, k, l : entier) /* surcharge */</span></p> <p class="MsoHeader"><span style= 'font-family:"Courier New"'> PROCEDURE affiche () /* redéfinition */</span></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'>FCLASSE</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>La classe B possède ici quatre membres données de type entier. Les membres x et y sont hérités de la classe A, le membre z est ajouté, le membre x est redéfini. Un membre "donnée" redéfini ne remplace pas le membre correspondant de la classe de base, il est ajouté. Chaque objet de la classe B possédera donc les membres données x, y, z et x de A.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>La classe B a accès aux cinq méthodes membres : initial(données : i, j, k, l : entier), initial(données : i, j : entier), affiche(), A::affiche() et affiche_x().</span></p> <p class="MsoNormal"><i><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></i></p> <p class="MsoNormal"><i><u><span style='font-size:12.0pt'>Exercice d'application :</span></u></i></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Soient les variables unA et unB respectivement de classe A et B déclarés dans le programme principal. Remplir le tableau suivant :</span></p> <span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <table class="MsoNormalTable" border="1" cellspacing="0" cellpadding="0" width="694" style= 'width:520.55pt;border-collapse:collapse;border:none'> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal" align="center" style='text-align:center'> <span style='font-size:12.0pt'>Instruction ou</span></p> <p class="MsoNormal" align="center" style='text-align:center'> <span style='font-size:12.0pt'>partie d'instruction</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-left:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal" align="center" style='text-align:center'> <span style='font-size:12.0pt'>Localisation</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border:solid windowtext 1.0pt; border-left:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal" align="center" style='text-align:center'> <span style='font-size:12.0pt'>Membre utilisé ou erreur</span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>unB.initial (2, 3, 5, 6);</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>programme principal (pp)</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>initial (1, 2) ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe B</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>unB.initial (1, 2) ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>pp</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>x</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe B</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>A::x</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe B</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>x</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe A</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>x</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>pp</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>affiche_x () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe B</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>A::affiche_x () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe B</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>unB.affiche_x () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>pp</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>affiche () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe A</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>affiche () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe B</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>A::affiche () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe B</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>unB.affiche () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>pp</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>B::affiche () ;</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe A</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> <tr style='height:30.0pt'> <td width="194" valign="top" style= 'width:145.15pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>z</span></p> </td> <td width="194" valign="top" style= 'width:145.15pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>classe A</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt;height:30.0pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> </td> </tr> </table> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <h1><a name="node5" id="node5"></a><span style= 'text-decoration:none'>5.<span style= 'font:7.0pt "Times New Roman"'> </span></span> DERIVATIONS EN CASCADE</h1> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Une classe dérivée peut à son tour être spécialisée et devenir la classe de base d’une autre classe. Par exemple la classe « Deuxroues » peut hériter de « Véhicule » et les classes « Velo » et « Moto » peuvent hériter de « Deuxroues ». Dans ce cas, « Velo » et « Moto » héritent des membres de « Deuxroues » et implicitement des membres de « Véhicule » via « Deuxroues ».</span></p> <p class="H4" style='margin:0cm;margin-bottom:.0001pt'><span style= 'layout-grid-mode: both;font-weight:normal'> </span></p> <p class="H4" style='margin:0cm;margin-bottom:.0001pt'><span style= 'layout-grid-mode: both;font-weight:normal'>Toutes les classes dérivées peuvent utiliser directement les méthodes publiques (ainsi que les données publiques) des classes ancêtres (ancêtre direct ou non).</span></p> <p class="DefinitionTerm"><span style='layout-grid-mode:both'>Les principes présentés précédemment s’appliquent.</span></p> <span style= 'font-size:10.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"> </p> <h1><a name="node6" id="node6"></a><span style= 'text-decoration:none'>6.<span style= 'font:7.0pt "Times New Roman"'> </span></span> CODAGE EN JAVA</h1> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <h2 style='margin-left:18.0pt;text-indent:0cm'><a name="node7" id= "node7"></a><b>6.1. Dérivation et spécialisation</b></h2> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="DefinitionList"> </p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Véhicule</span></u></p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt; margin-left:18.0pt;margin-right:0cm'> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>class Véhicule</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> private int noveh;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> private String couleur;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> private float poids;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> </span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public void initialiser(int n, String c, float p) </span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> noveh = n;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> couleur=c;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> poids=p;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">} </span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public float donnerpoids()</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> {</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> return poids;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> </span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> public String donnercouleur()</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> {</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> return couleur;</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> }</span></p> <p class="DefinitionList" style= 'margin-left:0cm;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> </div> <p class="DefinitionTerm"> </p> <p class="DefinitionList"> </p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Voiture</span></u></p> <p class="MsoNormal"><span style= 'font-family:"Courier New"'> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-family: "Courier New"'> </span><span style= 'font-size:9.0pt;font-family:"Courier New"'>class Voiture <b>extends</b> Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> private int nbpassagers;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> private boolean métallisé;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public void initialiser(int n, String c, float p, int gens, boolean</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>métal) </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> initialiser(n, c, p);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nbpassagers=gens;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> métallisé=métal;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> } </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public int donnerpassagers()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> return nbpassagers;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public String donnercouleur()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> return <b>super</b>.donnercouleur() + (métallisé ?" métallisé":" mat");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Les possibilités d'accès sont identiques à ce qui a été vu en algorithmique.</span></p> <span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Test2 (pour tester Voiture et Véhicule)</span></u></p> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class Test2</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public static void main(String [] argv)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> Véhicule véh1 = new Véhicule(), véh2 = new Véhicule();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> Voiture voit1 = new Voiture(), voit2 = new Voiture();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> float pds;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> String couleur;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> int nbpas;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 12.0pt'> </span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> voit1.initialiser (1, "bleu", 1000); // Appel à initialiser de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> voit2.initialiser (2,"rouge",1500,7,true); // Appel à initialiser de Voiture</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> véh1.initialiser (1, "vert", 800); // Appel à initialiser de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> <s>véh2.initialiser (2, "jaune", 900, 7, true);</s> // Erreur</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> pds = voit1.donnerpoids(); // Appel à donnerpoids de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> pds = voit2.donnerpoids(); // Appel à donnerpoids de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> pds = véh1.donnerpoids(); // Appel à donnerpoids de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> couleur = voit1.donnercouleur(); // Appel à donnercouleur de Voiture</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> couleur = voit2.donnercouleur(); // Appel à donnercouleur de Voiture</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> couleur = véh1.donnercouleur(); // Appel à donnercouleur de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'> </p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nbpas = voit1.donnerpassagers(); // Appel à donnerpassagers</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> // Place 0 dans nbpas</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nbpas = voit2.donnerpassagers(); // Appel à donnerpassagers</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> // Place 7 dans nbpas</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> <s>nbpas = véh1.donnerpassagers();</s> // Erreur</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-family: "Courier New"'> </span></p> </div> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <h2 style='margin-left:18.0pt;text-indent:0cm'><a name="node8" id= "node8"></a><b>6.2. Le modificateur final</b></h2> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Nous connaissons déjà les modificateurs de visibilité (c'est à dire les statuts public et private), nous allons découvrir final (final peut s'employer avec un autre modificateur tel private ou public).</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Classes finales</span></u></b></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Cela signifie que la classe ne pourra pas être héritée. Il ne sera alors pas possible de la dériver.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'>Exemple :</span></p> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'>final</span></b> <span style= 'font-size:12.0pt'>class Velo</span></p> <p class="DefinitionTerm"><span style= 'layout-grid-mode:both'>{</span></p> <p class="DefinitionTerm"><span style= 'layout-grid-mode:both'>….</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>}</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Toute tentative donnera un message d'erreur à la compilation.</span></p> <b><span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span></b> <p class="MsoNormal"><b><span style= 'font-size:12.0pt'> </span></b></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Variables finales</span></u></b></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Ceci est utilisé pour déclarer des <b>constantes</b>. Généralement, il s'agira d'une donnée statique car on ne voit pas l'intérêt d'avoir une donnée de même valeur dans chaque objet.</span></p> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB">Exemples :</span></p> <p class="DefinitionTerm"><span lang="EN-GB" style= 'layout-grid-mode:both' xml:lang="EN-GB">public static final double EURO = 6.5569;</span></p> <p class="DefinitionList"><span lang="EN-GB" xml:lang= "EN-GB"> </span></p> <p class="DefinitionTerm"><span lang="EN-GB" xml:lang= "EN-GB">private static final double TVA = 19.6;</span></p> <p class="DefinitionTerm">On pourra en plus définir une fonction d'accès pour TVA comme on le fait pour une autre donnée privée.</p> <p class="DefinitionList" style='margin-left:0cm'><span lang= "EN-GB" xml:lang="EN-GB">public static double tva()</span></p> <p class="DefinitionList" style='margin-left:0cm'><span lang= "EN-GB" xml:lang="EN-GB">{</span></p> <p class="DefinitionList" style= 'margin-left:0cm;text-indent:18.0pt'><span lang="EN-GB" xml:lang= "EN-GB">return TVA;</span></p> <p class="DefinitionList" style='margin-left:0cm'>}</p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Méthodes finales</span></u></b></p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="DefinitionTerm"><span style='layout-grid-mode:both'>C'est une méthode qui ne peut être redéfinie. En revanche, elle pourra être surchargée.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <h2 style='margin-left:18.0pt;text-indent:0cm'><a name="node9" id= "node9"></a><b>6.3. Constructeurs</b></h2> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Il est impossible de construire un objet d'une classe dérivée avec le constructeur de la classe de base. Par exemple :</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Voiture v=new Véhicule(); // Provoque une erreur à la compilation</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Ce qui s'explique car le constructeur de Véhicule ne peut en aucun cas initialiser les données spécialisées de Voiture.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Véhicule2</span></u></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>class Véhicule2</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> private int noveh;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> String couleur;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> private float poids;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style='font-size:9.0pt;font-family:"Courier New"'>public Véhicule2 (int n, String c, float p) </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> noveh=n;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> couleur=c;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">poids=p;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> } </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public float donnerpoids()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> return poids;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public String donnercouleur()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> return couleur;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> </div> <span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Voiture2</span></u></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>class Voiture2 extends Véhicule2</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="DefinitionTerm" style='border:none;padding:0cm'> <span style= 'font-size: 9.0pt;font-family:"Courier New";layout-grid-mode:both'> private int nbpassagers;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> private boolean métallisé;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public Voiture2(int n, String c, float p, int gens, boolean métal) </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> <b>super</b>(n, c, p);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nbpassagers=gens;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> métallisé = métal;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> } </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public int donnerpassagers()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> return nbpassagers;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public String donnercouleur()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> return <b>super</b>.donnercouleur() + (métallisé ?" métallisé":" mat");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Test22 (pour tester Voiture2 et Véhicule2)</span></u></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class Test22</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public static void main(String [] argv)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span style='font-size:9.0pt; font-family:"Courier New"'>Véhicule2 véh1 = new Véhicule2(1, "vert", 800);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> <s>Véhicule2 véh2 = new Véhicule2(2,"jaune",900,7,true);</s> // véh2 ne sera pas // créé, il y aura erreur</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> Voiture2 voit1 = new Voiture2(1, "bleu", 1000<b>,</b> 0, false),</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> voit2 = new Voiture2(2, "rouge", 1500, 7, true);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> float pds;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> int nbpas;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> String couleur; </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> pds = voit1.donnerpoids(); // Appel à donnerpoids de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> pds = voit2.donnerpoids(); // Appel à donnerpoids de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> pds = véh1.donnerpoids(); // Appel à donnerpoids de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> couleur = voit1.donnercouleur(); // Appel à donnercouleur de Voiture</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> couleur = voit2.donnercouleur(); // Appel à donnercouleur de Voiture</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> couleur = véh1.donnercouleur(); // Appel à donnercouleur de Véhicule</span></p> <p class="MsoNormal" style='border:none;padding:0cm'> </p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nbpas = voit1.donnerpassagers(); // Appel à donnerpassagers</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> // Place 0 dans nbpas</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nbpas = voit2.donnerpassagers(); // Appel à donnerpassagers</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> // Place 7 dans nbpas</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> <s>nbpas = véh1.donnerpassagers();</s> // Erreur</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-family: "Courier New"'> </span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <b><u><span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span></u></b> <p class="MsoNormal"><u><span style='font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Remarques :</span></u></b></p> <p class="MsoNormal"><u><span style='font-size:11.0pt'><span style= 'text-decoration: none'> </span></span></u></p> <p class="MsoNormal"><span style='font-size:12.0pt'>. A partir du moment où la classe de base ne possède pas de constructeur par défaut, il est impératif de prévoir un constructeur pour la classe dérivée ne serait-ce que pour transmettre</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>les paramètres nécessaires au constructeur de la classe de base.</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Si la classe de base possède un constructeur par défaut (implicite c'est à dire aucun constructeur défini ou bien explicite), la classe dérivée n'est pas obligée de mettre en place un constructeur.</span></p> <p class="MsoNormal"><span style= 'font-size:11.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>. Si on avait souhaité qu'une voiture puisse être construite avec ou sans paramètres, il aurait fallu prévoir en plus un constructeur sans paramètres pour Voiture2 et pour Véhicule2.</span></p> <p class="MsoNormal"><i><span style= 'font-size:12.0pt'> </span></i></p> <p class="MsoNormal"><span style='font-size:12.0pt'>public Véhicule2 () </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>{</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> Code éventuel</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>}</span></p> <p class="MsoNormal"><i><span style= 'font-size:12.0pt'> </span></i></p> <p class="MsoNormal"><span style='font-size:12.0pt'>public Voiture2 () </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>{</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> Code éventuel</span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>}</span></p> <p class="MsoNormal"><i><span style= 'font-size:11.0pt'> </span></i></p> <p class="MsoNormal"><i><span style= 'font-size:11.0pt'> </span></i></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Exercice d'application sur les constructeurs</span></u></b></p> <p class="MsoNormal"> </p> <p class="MsoNormal"><span style='font-size:12.0pt'>Soient les classes A et B :</span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 1.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class A</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> private int x, y;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>public A() {} // constructeur par défaut</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public A (int i, int j) // constructeur paramétré</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size:9.0pt; font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> x = i ;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> y = j;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">}</span></p> </div> <p class="MsoNormal"><span lang="EN-GB" xml:lang= "EN-GB"> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:0cm 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class B extends A</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> private int x, z;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public B (){} </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public B (int i, int j, int k, int l)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> super(i,j) ; //appel du constructeur de A avec ses paramètres</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> x = k;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> z = l;</span></p> <p class="MsoHeader" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Donner l'objet obtenu (ou erreur) pour chaque instruction de création d’objet :</span></p> <table class="MsoNormalTable" border="1" cellspacing="0" cellpadding="0" style='border-collapse:collapse;border:none'> <tr> <td width="307" valign="top" style= 'width:230.25pt;border:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><span style= 'font-size:12.0pt'>Instruction</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border:solid windowtext 1.0pt; border-left:none;padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><span style='font-size:12.0pt'>Objet créé ou erreur</span></p> </td> </tr> <tr> <td width="307" valign="top" style= 'width:230.25pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><b><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB">B unb=new B() ;</span></b></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> </td> </tr> <tr> <td width="307" valign="top" style= 'width:230.25pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><b><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB">B unb=new B(2,3,4,5) ;</span></b></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> </td> </tr> <tr> <td width="307" valign="top" style= 'width:230.25pt;border:solid windowtext 1.0pt; border-top:none;padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><b><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB">B unb =new B(1,2)</span></b><span lang= "EN-GB" style='font-size:12.0pt' xml:lang="EN-GB">;</span></p> </td> <td width="307" valign="top" style= 'width:230.25pt;border-top:none;border-left: none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt; padding:0cm 3.5pt 0cm 3.5pt'> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> </td> </tr> </table> <span lang="EN-GB" style= 'font-size:12.0pt;font-family:"Times New Roman"' xml:lang= "EN-GB"><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> <h2 style='margin-left:18.0pt;text-indent:0cm'><a name="node10" id= "node10"></a><b>6.4. Dérivation de classes du JDK</b></h2> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="DefinitionTerm"><span style='layout-grid-mode:both'>Il est tout à fait possible de dériver les classes du JDK.</span></p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="MsoNormal"><b><u><span style='font-size:12.0pt'>Exemple : création d'une classe Férié dérivée de la classe GregorianCalendar</span></u></b></p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Férié</span></u></p> <p class="MsoNormal"> </p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>import java.util.GregorianCalendar;</span></p> <p class="DefinitionTerm" style='border:none;padding:0cm'> <span style='layout-grid-mode: both'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>class Férié extends GregorianCalendar</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> private String nom;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> public Férié(String n, int j, int m, int a)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size: 9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> super(a, m-1, j);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>nom=n;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public String rendnom()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> {</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> return nom;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-left:18.0pt;text-indent:-18.0pt'><span style= 'font-size:8.0pt;font-family:Wingdings'>q<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Ecriture de la classe Progférié qui utilise la classe Férié</span></u></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class Progférié</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public static void main(String [] argv)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> Férié jourférié = new Férié("Noel",25, 12, 2001);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size: 9.0pt;font-family:"Courier New"' xml:lang="EN-GB">int jour = jourférié.get(Férié.DAY_OF_MONTH);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style='font-size:9.0pt;font-family:"Courier New"'>int mois = jourférié.get(Férié.MONTH)+1;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> int an = jourférié.get(Férié.YEAR);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> int quant = jourférié.get(Férié.DAY_OF_YEAR);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> System.out.println (jourférié.rendnom() + " "+jour + " " + mois + " " + an);</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> System.out.println ("Ce sera le " + quant + "eme jour de l'annee");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'> <u><span style='font-size: 9.0pt;font-family:"Courier New"'><span style='text-decoration:none'> </span></span></u></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <span style= 'font-size:10.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"> </p> <p class="MsoNormal"><b><u><span style= 'font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></b></p> <h2 style='margin-left:18.0pt;text-indent:0cm'><a name="node11" id= "node11"></a><b>6.5. Compléments</b></h2> <p class="DefinitionTerm"><span style= 'layout-grid-mode:both'> </span></p> <h3 align="left" style= 'margin-left:35.4pt;text-align:left;text-indent:0cm'><a name= "node12" id="node12"></a>6.5.1. Classes et méthodes abstraites</h3> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Une classe qui n’est utilisée que pour être dérivée peut être définie comme <b>abstraite</b>. Toute instanciation est alors impossible.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="DefinitionTerm"><span style= 'layout-grid-mode:both'>Exemple : soit la hiérarchie suivante :</span></p> <p class="DefinitionList"> </p> <p class="MsoNormal"></p> <table cellpadding="0" cellspacing="0" align="left"> <tr> <td width="314" height="0"></td> </tr> <tr> <td></td> <td><img width="73" height="64" src= "S36_Cours_Atelier6_complet_fichiers/image001.gif" alt= "image" /></td> </tr> </table> <br clear="all" /> <img width="121" height="30" src= "S36_Cours_Atelier6_complet_fichiers/image002.gif" align="left" hspace="12" alt="Zone de Texte: Oiseau " /> <table cellpadding="0" cellspacing="0" align="left"> <tr> <td width="29" height="0"></td> </tr> <tr> <td></td> <td><img width="231" height="94" src= "S36_Cours_Atelier6_complet_fichiers/image003.gif" alt= "image" /></td> </tr> </table> <br clear="all" /> <p class="MsoNormal"><u><span style='font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></p> <p class="MsoNormal"><u><span style='font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></p> <p class="MsoNormal"><u><span style='font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></p> <p class="MsoNormal" style= 'margin-left:36.0pt;text-indent:-36.0pt'><span lang="EN-GB" style= 'font-size:12.0pt;font-family:Symbol' xml:lang= "EN-GB">·<span style='font:7.0pt "Times New Roman"'> </span></span> <u><span lang="EN-GB" style='font-size:12.0pt' xml:lang= "EN-GB">Classe Animal :</span></u></p> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">abstract</span></b> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang="EN-GB">class Animal</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">String prénom;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public Animal(String p)</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> prénom = p;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>public String rendprénom()</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> return prénom;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><b><span style= 'font-size:9.0pt;font-family:"Courier New"'>abstract</span></b> <span style='font-size:9.0pt;font-family:"Courier New"'>public void crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Toutes les <b>méthodes déclarées abstraites</b> dans la classe abstraite <b>devront être redéfinies</b> (donc <b>{</b> bloc <b>}</b> obligatoire avec bloc éventuellement vide) dans chaque classe dérivée que l'on veut instancier. Si l'une des méthodes abstraites n'est pas redéfinie dans une classe dérivée, cette classe dérivée est elle-même abstraite et doit être déclarée comme telle.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>La déclaration d'une méthode abstraite dans une classe rend la classe abstraite et nous oblige à la déclarer comme telle.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Toutes les méthodes non abstraites d'une classe abstraite ne sont pas obligatoirement redéfinies dans les classes dérivées mais peuvent l'être.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><u><span style='font-size:12.0pt'><span style= 'text-decoration: none'> </span></span></u></p> <p class="MsoNormal" style= 'margin-left:36.0pt;text-indent:-36.0pt'><span lang="EN-GB" style= 'font-size:12.0pt;font-family:Symbol' xml:lang= "EN-GB">·<span style='font:7.0pt "Times New Roman"'> </span></span> <u><span lang="EN-GB" style='font-size:12.0pt' xml:lang= "EN-GB">Classe Ovipare :</span></u></p> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">abstract</span></b> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang="EN-GB">class Ovipare extends Animal</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public Ovipare(String p)</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> super(p);</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><b><span style= 'font-size:9.0pt;font-family:"Courier New"'>abstract</span></b> <span style='font-size:9.0pt;font-family:"Courier New"'>public void crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Un constructeur ne peut pas être abstrait.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="DefinitionTerm"><span style='layout-grid-mode:both'>Dans cet exemple, on est obligé de définir le constructeur dans les classes dérivées car la classe de base (Animal) ne comprend pas de constructeur par défaut. Mais si on avait</span></p> <p class="DefinitionTerm"><span style= 'layout-grid-mode:both'>défini :</span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="DefinitionTerm" style='border:none;padding:0cm'> <span style= 'font-size: 9.0pt;font-family:"Courier New";layout-grid-mode:both'>public Animal(String p)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> prénom = p;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>public Animal()</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt'> </span></p> </div> <p class="MsoNormal"><span style='font-size:12.0pt'>Alors, il n'y aurait pas obligation de redéfinir le constructeur.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-left:36.0pt;text-indent:-36.0pt'><span style= 'font-size:12.0pt;font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Classe Oiseau :</span></u></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>class Oiseau extends Ovipare</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>public Oiseau(String p)</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> super(p);</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>public void crier()</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> System.out.println ("Cuicui");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Ainsi que nous l'avons dit ci-avant, il est obligatoire de redéfinir (donc {bloc} obligatoire avec bloc éventuellement vide) la méthode crier dans les classes que l'on veut instancier.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <span style= 'font-size:12.0pt;font-family:"Times New Roman"'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:36.0pt;text-indent:-36.0pt'> <span lang="EN-GB" style='font-size:12.0pt; font-family:Symbol' xml:lang="EN-GB">·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span lang="EN-GB" style='font-size:12.0pt' xml:lang= "EN-GB">Classe Mammifère :</span></u></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">abstract</span></b> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang="EN-GB">class Mammifère extends Animal</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">String race;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public Mammifère(String p, String r)</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> super(p);</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> race = r;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public String rendrace()</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> return race;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">abstract public void crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:36.0pt;text-indent:-36.0pt'> <span style='font-size:12.0pt; font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Classe Chien :</span></u></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>class Chien extends Mammifère</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public Chien(String p, String r)</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> super(p, r);</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public void crier()</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> System.out.println ("Ouah-Ouah");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> }</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">}</span></p> </div> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:36.0pt;text-indent:-36.0pt'> <span lang="EN-GB" style='font-size:12.0pt; font-family:Symbol' xml:lang="EN-GB">·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span lang="EN-GB" style='font-size:12.0pt' xml:lang= "EN-GB">Classe Chat :</span></u></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class Chat extends Mammifère</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public Chat(String p, String r)</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> super(p, r);</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">public void crier()</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> System.out.println ("Miaou-Miaou");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'>}</span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:36.0pt;text-indent:-36.0pt'> <span style='font-size:12.0pt; font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Classe pour les tests :</span></u></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class</span> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">TestAnimaux</span></p> <p class="DefinitionTerm" style='border:none;padding:0cm'> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";layout-grid-mode:both' xml:lang="EN-GB">{ </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public static void main(String [] argv)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> Chien milou = new Chien("Milou", "Berger des Pyrénées");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang="EN-GB">Chat tigri = new Chat("Tigri", "Angora");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> Oiseau nestor = new Oiseau("Nestor");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> milou.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> tigri.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> nestor.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> } </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB">}</span></p> </div> <span lang="EN-GB" style= 'font-size:12.0pt;font-family:"Times New Roman"' xml:lang= "EN-GB"><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB"> </span></p> <p class="MsoNormal"><span lang="EN-GB" style='font-size:12.0pt' xml:lang="EN-GB">Remarques :</span></p> <p class="MsoNormal" style= 'margin-left:36.0pt;text-indent:-21.8pt'><span style= 'font-size:12.0pt;font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <span style='font-size:12.0pt'>Ovipare et Mammifère sont obligées d'être abstraites ou bien de redéfinir (donc {bloc} obligatoire avec bloc éventuellement vide) la méthode crier.</span></p> <p class="MsoNormal" style='margin-left:35.4pt'><span style= 'font-size:12.0pt'>De toute façon :</span></p> <p class="MsoBodyTextIndent" style= 'margin-left:78.75pt;text-indent:-24.75pt'>-<span style= 'font:7.0pt "Times New Roman"'> </span> On considère que ces 2 classes ne peuvent être instanciées donc on les déclare abstraites.</p> <p class="MsoNormal" style= 'margin-left:78.75pt;text-indent:-24.75pt'><span style= 'font-size:12.0pt'>-<span style= 'font:7.0pt "Times New Roman"'> </span></span> <span style='font-size:12.0pt'>On considère que le cri d'un mammifère ou d'un ovipare est une notion abstraite donc on ne peut donner un corps à la méthode crier dans Ovipare et dans Mammifère donc on déclare la méthode crier comme abstraite dans ces 2 classes.</span></p> <p class="MsoNormal" style= 'margin-left:35.45pt;text-indent:-21.25pt'><span style= 'font-size:12.0pt;font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <span style='font-size:12.0pt'>Une classe peut être déclarée abstraite même si elle ne contient aucune méthode abstraite.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal" style='margin-top:6.0pt;text-indent:35.45pt'> <b><span style='font-size:12.0pt;color:black'>6.5.2. Le polymorphisme</span></b></p> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'> </span></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:35.7pt;text-indent:-17.85pt'> <b><i><span style='font-size:12.0pt; color:black'>a.<span style= 'font:7.0pt "Times New Roman"'> </span></span></i></b> <b><i><span style= 'font-size:12.0pt;color:black'>Principe</span></i></b></p> <p class="MsoNormal"><span style='font-size:12.0pt;color:black'>Le fait qu'une référence du type de la classe parente désigne un objet d'une classe dérivée s'appelle le <b>surcasting</b>.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt;color:black'>Ex :</span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New";color:black'>Animal monanimal = new Chien("Rantanplan", "Setter");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New";color:black'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New";color:black'>ou en version longue :</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New";color:black'> </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB">Animal monanimal;</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB">monanimal = new Chien("Rantanplan", "Setter");</span></p> </div> <p class="MsoNormal" style= 'margin-top:6.0pt;margin-right:0cm;margin-bottom:6.0pt; margin-left:0cm'> <span style='font-size:12.0pt;color:black'>Remarque : il est impossible de faire l'opération inverse ainsi que nous l'avons déjà vu, par exemple il est impossible d'écrire :</span></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><s><span lang= "EN-GB" style='font-size:12.0pt;color:black' xml:lang="EN-GB">Chien monanimal = new Animal("Rantanplan", "Setter");</span></s></p> </div> <p class="MsoNormal"><span lang="EN-GB" style= 'font-size:12.0pt;color:black' xml:lang="EN-GB"> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Le <b>typage (ou liaison) dynamique (ou tardive)</b> consiste à déterminer la méthode à appeler seulement lors de l’exécution en prenant en compte le type effectif de l’objet désigné par le handle et non le type déclaré du handle.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt'>Java fonctionne par typage tardif sauf pour les méthodes déclarées avec le modificateur <i>final</i>.</span></p> <p class="DefinitionTerm"><span style='layout-grid-mode:both'>Nous allons voir un exemple de typage tardif avec la nouvelle version de la classe de test.</span></p> <p class="MsoNormal"><u><span style= 'text-decoration:none'> </span></u></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:36.0pt;text-indent:-36.0pt'> <span style='font-size:12.0pt; font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Nouvelle version de la classe de test :</span></u></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class</span></b> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">TestAnimaux2</span></p> <p class="DefinitionTerm" style='border:none;padding:0cm'> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";layout-grid-mode:both' xml:lang="EN-GB">{ </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public static void main(String [] argv)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> Animal milou = new Chien("Milou", "Berger des Pyrénées");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang="EN-GB">Animal tigri = new Chat("Tigri", "Angora");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> Animal nestor = new Oiseau("Nestor");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>milou.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> tigri.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nestor.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> } </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New";color:black'>}</span></p> </div> <span style= 'font-size:12.0pt;font-family:"Times New Roman";color:black'><br clear="all" style='page-break-before:always' /></span> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'> </span></p> <p class="MsoNormal"><span style='font-size:12.0pt;color:black'>Ce sont bien les méthodes crier des classes dérivées qui sont appelées au moment de l'exécution. Ceci n'a rien à voir avec le fait que la méthode crier soit abstract.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'> </span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'>Attention, il faut que la méthode existe dans la classe Animal (même si ce n'est pas celle qui sera exécutée) car sinon il y a une erreur à la compilation.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'> </span></p> <p class="MsoNormal"><b><span style='font-size:12.0pt'>Le polymorphisme se définit par le fait que les instances des différentes classes répondent à la même méthode mais d'une façon appropriée à chaque classe. Une même instruction provoquera l'appel de telle ou telle méthode en fonction de la classe de l'objet effectivement désigné par le handle au moment de l'exécution.</span></b></p> <p class="MsoNormal"><b><span style='font-size:12.0pt'>Le polymorphisme est possible grâce au système de liaison tardive.</span></b></p> <p class="MsoNormal"><u><span style= 'text-decoration:none'> </span></u></p> <p class="MsoNormal"><u><span style= 'text-decoration:none'> </span></u></p> <p class="MsoNormal" style='margin-bottom:6.0pt'><b><i><span style= 'font-size: 12.0pt'> b. Passage de paramètres et polymorphisme</span></i></b></p> <p class="MsoNormal"><span style='font-size:12.0pt;color:black'>On va voir qu'une référence transmise explicitement en paramètre est également polymorphe.</span></p> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'> </span></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:36.0pt;text-indent:-36.0pt'> <span style='font-size:12.0pt; font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Nouvelle version de la classe Animal :</span></u></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 4.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB">abstract class Animal</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB">{</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">String prénom;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">public Animal(String p)</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB"> prénom = p;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">public String rendprénom()</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB"> return prénom;</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">}</span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">abstract public void crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB"> </span></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><b><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">public void copain(Animal a)</span></b></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><b><span lang="EN-GB" style='font-size:9.0pt;font-family:"Courier New";color:black' xml:lang="EN-GB">{</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB"> System.out.println(rendprénom() + " et " +</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB"> a.rendprénom() + " sont copains");</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";color:black' xml:lang= "EN-GB"> </span></b> <b><span style= 'font-size:9.0pt;font-family:"Courier New";color:black'>System.out.println("Voici les cris que l'on entend : ");</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 9.0pt;font-family:"Courier New";color:black'> crier();</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'> <b><span style='font-size: 9.0pt;font-family:"Courier New";color:black'> a.crier();</span></b></p> <p class="MsoNormal" style= 'text-indent:35.4pt;border:none;padding:0cm'><b><span style= 'font-size:9.0pt;font-family:"Courier New";color:black'>}</span></b></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New";color:black'>}</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:12.0pt; color:black'> </span></p> </div> <p class="MsoNormal"><span style= 'font-size:12.0pt;color:black'> </span></p> <p class="MsoNormal" style= 'margin-top:0cm;margin-right:0cm;margin-bottom:6.0pt; margin-left:36.0pt;text-indent:-36.0pt'> <span style='font-size:12.0pt; font-family:Symbol'>·<span style= 'font:7.0pt "Times New Roman"'> </span></span> <u><span style='font-size:12.0pt'>Nouvelle version de la classe de test :</span></u></p> <div style= 'border:solid windowtext 1.0pt;padding:1.0pt 3.0pt 1.0pt 4.0pt'> <p class="MsoNormal" style='border:none;padding:0cm'><b><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">class</span></b> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB">TestAnimaux3</span></p> <p class="DefinitionTerm" style='border:none;padding:0cm'> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New";layout-grid-mode:both' xml:lang="EN-GB">{ </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> public static void main(String [] argv)</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <span style= 'font-size:9.0pt;font-family:"Courier New"'>{</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> Animal milou = new Chien("Milou", "Berger des Pyrénées");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> </span> <span lang="EN-GB" style= 'font-size:9.0pt;font-family:"Courier New"' xml:lang="EN-GB">Animal tigri = new Chat("Tigri", "Angora");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> Animal nestor = new Oiseau("Nestor");</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span lang= "EN-GB" style='font-size:9.0pt;font-family:"Courier New"' xml:lang= "EN-GB"> </span> <b><span style= 'font-size:9.0pt;font-family:"Courier New"'>milou.copain(tigri);</span></b><span style='font-size:9.0pt;font-family:"Courier New"'> // Provoque l'affichage d'un msg disant que</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> // Milou et Tigri sont copains puis les cris</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> // de Milou et de Tigri</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> milou.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> tigri.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> nestor.crier();</span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New"'> } </span></p> <p class="MsoNormal" style='border:none;padding:0cm'><span style= 'font-size:9.0pt; font-family:"Courier New";color:black'>}</span></p> </div> <p class="MsoNormal"><span style='font-size:12.0pt;color:black'>On constate que le polymorphisme s'applique pour les 2 appels à crier qui figurent dans la méthode copain.</span></p> </div>
Table des matières
Sujets
Recherche
1. INTRODUCTION
2. UTILISATION DES MEMBRES « HERITES »
Les membres publics méthodes ou données de la classe de base sont utilisables avec un objet de la classe dérivée tout comme avec un objet de la classe de base.
3. SPECIALISATION
4. EXERCICE D'APPLICATION
5. DERIVATIONS EN CASCADE
6. CODAGE EN JAVA
6.1. Dérivation et spécialisation
6.2. Le modificateur final
6.3. Constructeurs
6.4. Dérivation de classes du JDK
6.5. Compléments
6.5.1. Classes et méthodes abstraites
1. INTRODUCTION
2. UTILISATION DES MEMBRES « HERITES »
3. SPECIALISATION
4. EXERCICE D'APPLICATION
5. DERIVATIONS EN CASCADE
6.1. Dérivation et spécialisation
6.2. Le modificateur final
6.3. Constructeurs
6.4. Dérivation de classes du JDK
6.5. Compléments
6.5.1. Classes et méthodes abstraites
6. CODAGE EN JAVA
Les membres publics méthodes ou données de la classe de base sont utilisables avec un objet de la classe dérivée tout comme avec un objet de la classe de base.
Générée avec
chmProcessor
Générée avec
chmProcessor