【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

package FuZi;

public class People {
    void a(){System.out.println("People");}
}

package FuZi;

public class Student extends People{
    void a(){System.out.println("Student");}
    public static void main(String args[]){
        People p=new Student();
        p.a();
    }

}

 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