【每日日报】第二十四天

1 5.8上机练习

当父类定义为final时子类重载该函数会出现报错

1 package FuZi;
2 
3 public class People {
4     void a(){System.out.println("People");}
5 }

 1 package FuZi;
 2 
 3 public class Student extends People{
 4     void a(){System.out.println("Student");}
 5     public static void main(String args[]){
 6         People p=new Student();
 7         p.a();
 8     }
 9 
10 }

当新建 People p=new Student();

当Student p=new People();

2 没什么问题

3 明天继续看手册