面向对象—存款取款

 1 String zhanghu;//定义账户
 2    double cunkuanyue;//定义存款余额
 3    Account(String zhanghu,double cunkuanyue)//初始化账户，存款余额
 4    {
 5        //this. 代表当前类
 6        this.zhanghu=zhanghu;
 7        this.cunkuanyue=cunkuanyue;
 8    }
 9    //存款  
10    //有返回值带参数的方法
11     double cunkuan(double qianshu) 
12     {
13         // 验证
14         if (qianshu < 1) 
15         {
16             System.out.println("输入错误");
17 
18         } 
19         else
20         {
21             System.out.println("存了" + qianshu);
22             this.cunkuanyue += qianshu;
23         }
24         return this.cunkuanyue;
25     }
26    
27 
28    
29  //取款
30    //有返回值带参数的方法
31     double qukuan(double qianshu) {
32         if (qianshu > this.cunkuanyue) {
33             System.out.println("余额不足");
34 
35         } else {
36             System.out.println("取了" + qianshu);
37             this.cunkuanyue -= qianshu;
38         }
39         return this.cunkuanyue;
40     }
41    //查询余额
42    //有返回值无参数的方法
43    double getyue()
44    {
45        return this.cunkuanyue;
46    }
47     
48     
49     public static void main(String[] args) {
50         // TODO 自动生成的方法存根
51         Account account=new Account("123456",1000);
52         account.cunkuan(100);
53         System.out.println("查询余额"+account.getyue());
54         account.qukuan(300);
55         System.out.println("查询余额"+account.getyue());
56     }