(OJ)Java面向对象-多态

多态

Problem Description

完成下列多态程序：

class Animal {
   public void eat(){
      System.out.println("eat");
   }
}
  
class Dog extends Animal {
   public void eat() {
     System.out.println("eat bones");
   }
 
   public void lookDoor() {
     System.out.println("look door");
   }
}
 
class Cat extends Animal {
  public void eat() {
     System.out.println("eat fish");
  }
 
 public void playGame() {
    System.out.println("hide-and-seek");
 }
}
 
class Main {
  public static void main(String[] args) {
    Animal a,b;
   // 你的代码嵌在这里
   a.eat();
   b.eat();
  }
}

Output Description

eat bones

eat fish

解题代码

// 多态 子类的实例赋值给父类的引用
// dog类的实例赋值给Animal的引用
a = new Dog();
// cat类的实例赋值给Animal的引用
b = new Cat();