1 package com.oop.demo5;
 2 //在Java中， 所有的类，都默认直接或者间接继承object
 3 //Person人: 父类 ctrl+H 展开继承关系树
 4 public class Person {
 5     //public
 6     //protected
 7     //default
 8     //private
 9     private int money = 10_0000_0000;
10 
11     public void say() {
12         System.out.println("说了一句话");
13     }
14 
15     public int getMoney() {
16         return money;
17     }
18 
19     public void setMoney(int money) {
20         this.money = money;
21     }
22 }

 1 package com.oop.demo5;
 2 //学生 is  人：派生类，子类
 3 //子类继承了父类，就会拥有父类的全部方法!
 4 
 5 public class Student extends Person {
 6 
 7 }
 8 
 9 package com.oop.demo5;
10 
11 public class Teacher extends Person {
12 }