父类:

    1. package com.demo2;
    2. //定义父类
    3. public class Phone {
    4. int num=100;
    5. }

    子类:

    package com.demo2;
    public class NewPhone extends Phone {
        int num=100;
        public void testNum(){
            System.out.println(super.num); //访问父类成员变量
        }
    }