java入门第二季--多态--多态中的引用类型转换

多态中的引用类型转换

代码

/javaDemo4/src/com/imooc/Animal.java

package com.imooc;

public class Animal {
    
}

/javaDemo4/src/com/imooc/Dog.java

package com.imooc;

public class Dog extends Animal {

}

/javaDemo4/src/com/imooc/Cat.java

package com.imooc;

public class Cat extends Animal {

}

Initail.java

package com.imooc;

public class Initail {

    public static void main(String[] args) {
        
        Dog dog = new Dog();
        Animal animal = dog;  //自动类型提升，向上类型转换
        Dog dog2 = (Dog)animal; //向下类型转换 强制类型转型
        
        if(animal instanceof Cat) {
            Cat cat = (Cat)animal;
        }else {
            System.out.println("无法进行类型转换");
        }
    }

}