If you don't go after what you want, you'll never have it. If you don't step forward, you're always in the same place.

Java attack - Java 的封装，继承，多态

Java 的封装，继承，多态

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 多态

 

 

 

Java 对象的向下转型和向上转型

 

 

 

 

 

 

 

posted @ 2020-03-29 12:55  BlackAnts  阅读(143)  评论(0)    收藏  举报