Javaでポリモフィズム動物園(プログラミングの練習)
JavaはJSやPHPやRubyと比べて難しいと聞いた。
Javaの練習。
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import java.util.*; public class Main { public static void main(String[] args){ List<Animal> animals = new ArrayList<>(); animals.add(new Cat(3)); animals.add(new Dog(5)); animals.add(new Mike(7)); Breeder b = new Breeder(); b.breedAll(animals); } } class Breeder { public void breed(Animal a){ a.cry(); } public void breedAll(List<Animal> animals){ for(Animal a : animals){ this.breed(a); } } } abstract class Animal { protected int age; public Animal(int age){ if(age < 0){ age = 0; } this.age = age; } public abstract void cry(); } class Cat extends Animal { public Cat(int age){ super(age); } public void cry(){ System.out.println("ニャー(" + super.age +")"); } } class Dog extends Animal { public Dog(int age){ super(age); } public void cry(){ System.out.println("ワン(" + super.age +")"); } } class Mike extends Cat { public Mike(int age){ super(age); } public void cry(){ System.out.println("ミケニャー(" + super.age +")"); } } |
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ニャー(3) ワン(5) ミケニャー(7) |
