多态性（编译砍左，运行看右）

 

 

 

 多态性的使用

 

public class AnimalTest {

    public static void main(String[] args) {
        AnimalTest test =new AnimalTest();
        test.func(new Cat());
        test.func(new Dog());
    }

    public void func(Animal animal){//Animal animal =new Dog();
        animal.eat();
        animal.shout();
    }
}
class Animal{
    public void eat(){
        System.out.println("动物进食");
    }
    public void  shout(){
        System.out.println("动物，叫");
    }

}

class Dog extends Animal{
    public void eat(){
        System.out.println("狗吃鱼");
    }
    public void shout(){
        System.out.println("汪汪汪");
    }

}
class Cat extends Animal{
    public void eat(){
        System.out.println("猫吃骨头");
    }
    public void shout(){
        System.out.println("喵喵喵");
    }
}

 

 属性无法别重写