子父类继承时，override例子

1、三个包，每个包包含一个java

package com.modifi.test1;

public class Animal {
    public String move() {  //Line2 
        return "Unspecified";
    }
    public static void main(String[] argv) {
        Animal a1;
        a1 = new Bird();
        System.out.println(a1.move());
    }
}
class Bird extends Animal {
    public String move() {  //Line12
        return "Fly";
    }

}

运行结果Fly

 

二、

package com.modifi.test2;

public class Animal {
    public static String move() {  //Line2 
        return "Unspecified";
    }
    public static void main(String[] argv) {
        Animal a1= new Bird();
        System.out.println(a1.move());
    }
}
class Bird extends Animal {
    public static String move() {  //Line12
        return "Fly";
    }

}

运行结果：Unspecified

package com.modifi.test3;

public class Animal {
    private String move() {  //Line2 
        return "Unspecified";
    }
    public static void main(String[] argv) {
        Animal a1= new Bird();
        System.out.println(a1.move());
    }
}
class Bird extends Animal {
    public String move() {  //Line12
        return "Fly";
    }

}

 

运行结果：Unspecified

 

 

不理解！！