package com.text_1; public class Account { //帐号 String zhanghao; //存款余额 double cunkuanyue; Account(String zhanghao,double cunkuanyue) { this.zhanghao=zhanghao; this.cunkuanyue=cunkuanyue; } //存款;并得到余额 //有返回值带参数的方法 double cunkuan(double qianshu)//接受参数() { //验证 if(qianshu<0) { System.out.println("钱数错误"); //终止 } else { System.out.println("我存了"+qianshu); this.cunkuanyue+=qianshu; } return this.getyue(); } //取款 //无返回值带参数的方法 void qukuan(double qianshu ) { if(qianshu>this.cunkuanyue) { System.out.println("余额不足"); //终止 return; } System.out.println("我取了"+qianshu); this.cunkuanyue-=qianshu; } //查询余额 //有返回值,无参数的构造方法 double getyue() { return this.cunkuanyue; } public static void main(String[] args) { Account ac=new Account("123456",1000); ac.cunkuan(100); System.out.println("查询余额="+ac.getyue()); ac.qukuan(300); System.out.println("查询余额="+ac.getyue()); } }