使用javascript函数编写简单银行取钱存钱流程

const readline = require('readline-sync')//引用readline-sync
let arr = [['zhang', '123', 2000], ['yang', '123456', 3000]];
//登陆 
let add = function () {
  let s = 2;//输入错误的次数
  while (true) {
    console.log('请输入用户名：');
    let user = readline.question();
    console.log('请输入密码：');
    let password = readline.question();
    for (let i = 0; i < arr.length; i++) {   
      if (user === arr[i][0] && password === arr[i][1]) {
        console.log('欢迎你，登陆成功');
        mean(i);
        return;
      }
    }
    //输入不正确，超过三次
    if (s != 0) {
      console.log(`密码或账户有误，你还有${s}次机会，请重新输入！`);
      s--;
    } else {
      console.log('对不起，账户锁定！');
      break;
    }
  }
}
//存款
let fn1 = function (i) {
  console.log('存款');
  console.log('请输入存款金额：');
  let cunkuan = readline.question() - 0;
  arr[i][2]+= cunkuan;
  console.log('系统正在为你存钱请稍等。。。。。\n存钱成功您当前余额为' + arr[i][2]);
}
//取款
let fn2 = function (i) {
  console.log('取款');
  console.log('请输入取款金额：');
  let qukuan = readline.question() - 0;
  if (qukuan > arr[i][2]) {
    console.log('对不起你的余额不足！，请重新输入金额或者退出');
  } else {
    arr[i][2] = arr[i][2] - qukuan;
    console.log('正在为你取钱。。。。。\n您当前余额为：' + arr[i][2]);
  }
}
//查看
let fn3 = function (i) {
  console.log('查看');
  console.log('正在查询。。。。\n您当前的余额为：' + arr[i][2]);
}
//退出
let fn4 = function () {
  console.log('退出');
  console.log('欢迎你下次使用！');
}
//流程
let mean = function (i) {
  for (let yewu = 1; yewu >= 1; yewu++) {
    console.log('请选择业务：\n1.存款： \n2.取款： \n3.查看： \n4.退出：');
    let yewu = readline.question() - 0;
    switch (yewu) {
      case 1:
        fn1(i);
        continue;
      case 2:
        fn2(i);
        continue;
      case 3:
        fn3(i);
        continue;
      case 4:
        fn4();
        return;
    }break;
  }
}
add();