const readline = require('readline-sync')//引用readline-synclet arr = [['zhang', '123', 2000], ['yang', '123456', 3000]];//登陸 let add = function () {  let s = 2;//輸入錯誤的次數  while (true) {    console.log('請輸入用戶名：');    let user = readline.question();    console.log('請輸入密碼：');    let password = readline.question();    for (let i = 0; i < arr.length; i++) {         if (user === arr[i][0] && password === arr[i][1]) {        console.log('歡迎你，登陸成功');        mean(i);        return;      }    }    //輸入不正確，超過三次    if (s != 0) {      console.log(`密碼或賬戶有誤，你還有${s}次機會，請重新輸入！`);      s--;    } else {      console.log('對不起，賬戶鎖定！');      break;    }  }}//存款let fn1 = function (i) {  console.log('存款');  console.log('請輸入存款金額：');  let cunkuan = readline.question() - 0;  arr[i][2]+= cunkuan;  console.log('系統正在為你存錢請稍等。。。。。/n存錢成功您當前余額為' + arr[i][2]);}//取款let fn2 = function (i) {  console.log('取款');  console.log('請輸入取款金額：');  let qukuan = readline.question() - 0;  if (qukuan > arr[i][2]) {    console.log('對不起你的余額不足！，請重新輸入金額或者退出');  } else {    arr[i][2] = arr[i][2] - qukuan;    console.log('正在為你取錢。。。。。/n您當前余額為：' + arr[i][2]);  }}//查看let fn3 = function (i) {  console.log('查看');  console.log('正在查詢。。。。/n您當前的余額為：' + arr[i][2]);}//退出let fn4 = function () {  console.log('退出');  console.log('歡迎你下次使用！');}//流程let mean = function (i) {  for (let yewu = 1; yewu >= 1; yewu++) {    console.log('請選擇業務：/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();