Java【基础学习】向下转型和上转型例子

Java小白应付期末考试QWQ

 1 class Animal{
 2     public void move() {
 3         System.out.println(1);
 4     }
 5 }
 6 class Dog extends Animal{
 7     public void move() {
 8         System.out.println(2);
 9     }
10     public void bark() {
11         System.out.println(3);
12     }
13 }
14 public class Main{
15     public static void main(String[] args) {
16         Animal a1=new Animal();
17         a1.move();
18         Animal a2=new Dog();
19         a2.move();
20         Dog a3=(Dog)a2;
21         a3.bark();
22     }
23 }

 

posted @ 2019-12-10 18:27  pengge666  阅读(154)  评论(0)  编辑  收藏  举报