Java202608/src/main/java/com/sf/part05/oop_05/Animal.java

package main.java.com.sf.part05.oop_05;

public class Animal {
    int num = 10;
    public void eat() {
        System.out.println("动物吃食物");
    }
}


class Dog extends Animal {
    public void protectedHome() {
        System.out.println("狗看家");
    }
    int num = 20;
    @Override
    public void eat() {
        System.out.println("狗吃骨头");
    }
}

class Cat extends Animal {
    int num = 30;
    @Override
    public void eat() {
        System.out.println("猫吃鱼");
    }
}

class AnimalTest {
    public static void main(String[] args) {
        Dog dog = new Dog();
        dog.eat();
        Cat cat = new Cat();
        cat.eat();

        // 多态的形式
        //父类的引用指向了子类的对象
        // 父类/父接口  = new  子类();
        // 多态的方式调用方法   编译看左边，运行看右边
        // 多态调用属性/变量时，编译看左边，运行看左边
        Animal animal = new Dog();
        Animal animal1 = new Cat();
        animal.eat();
        int num = animal.num;
        // 强转  父类 - > 子类
        // instanceof  判断当前变量是否属于某种类型
        if(animal instanceof Dog){
            Dog dog1 = (Dog) animal;
            dog1.protectedHome();
        }
        System.out.println(num);
        animal1.eat();
    }
}