用javascript編寫簡單銀行取錢存錢流程（函數）

 1 const readline = require('readline-sync')//引用readline-sync
 2 let arr = [['zhang', '123', 2000], ['yang', '123456', 3000]];
 3 //登陸 
 4 let add = function () {
 5     let s = 2;//輸入錯誤的次數
 6     while (true) {
 7         console.log('請輸入用戶名：');
 8         let user = readline.question();
 9         console.log('請輸入密碼：');
10         let password = readline.question();
11         for (let i = 0; i < arr.length; i++) {     
12             if (user === arr[i][0] && password === arr[i][1]) {
13                 console.log('歡迎你，登陸成功');
14                 mean(i);
15                 return;
16             }
17         }
18         //輸入不正確，超過三次
19         if (s != 0) {
20             console.log(`密碼或賬戶有誤，你還有${s}次機會，請重新輸入！`);
21             s--;
22 
23         } else {
24             console.log('對不起，賬戶鎖定！');
25             break;
26         }
27     }
28 }
29 //存款
30 let fn1 = function (i) {
31 
32     console.log('存款');
33     console.log('請輸入存款金額：');
34     let cunkuan = readline.question() - 0;
35     arr[i][2]+= cunkuan;
36     console.log('系統正在為你存錢請稍等。。。。。\n存錢成功您當前餘額為' + arr[i][2]);
37 }
38 //取款
39 let fn2 = function (i) {
40     console.log('取款');
41     console.log('請輸入取款金額：');
42     let qukuan = readline.question() - 0;
43     if (qukuan > arr[i][2]) {
44         console.log('對不起你的餘額不足！，請重新輸入金額或者退出');
45     } else {
46         arr[i][2] = arr[i][2] - qukuan;
47         console.log('正在為你取錢。。。。。\n您當前餘額為：' + arr[i][2]);
48     }
49 }
50 //查看
51 let fn3 = function (i) {
52     console.log('查看');
53     console.log('正在查詢。。。。\n您當前的餘額為：' + arr[i][2]);
54 }
55 
56 //退出
57 
58 let fn4 = function () {
59     console.log('退出');
60     console.log('歡迎你下次使用！');
61 }
62 
63 //流程
64 let mean = function (i) {
65     for (let yewu = 1; yewu >= 1; yewu++) {
66         console.log('請選擇業務：\n1.存款： \n2.取款： \n3.查看： \n4.退出：');
67         let yewu = readline.question() - 0;
68         switch (yewu) {
69             case 1:
70                 fn1(i);
71                 continue;
72             case 2:
73                 fn2(i);
74                 continue;
75             case 3:
76                 fn3(i);
77                 continue;
78             case 4:
79                 fn4();
80                 return;
81         }break;
82     }
83 }
84 add();