簡易櫃員機 JAVAscript

const readline = require('readline-sync');
let arr = [['zhangsan','123456'],['lisi','123456']];
let menu='1.取款\n2.存款\n3.查看\n4.退出';

let isGister=false;    //定義初始登陸錯誤
let inputfalse=0;      //定義輸入錯誤次數

while(!isGister)
{
    console.log('請輸入賬號：')
    let username = readline.question();
    console.log('請輸入密碼：')
    let password = readline.question();
for ( i = 0; i < arr.length; i++) 
{
    if (username==arr[i][0]&&password==arr[i][1])
     {
        console.log('登陸成功');
        let flag=true;
        let balance=0;
        while(flag)
       {
            console.log(menu);
            console.log('請選擇：')
            let item = readline.question()-0;
            switch (item) {
                case 1:
                {   let flag1=true;
                     while(flag1)
                    {
                        console.log(`當前餘額爲${balance}元,請輸入取款金額：`)
                        let outmoney = readline.question();
                        balance-=outmoney;
                        console.log(`取款成功，當前餘額爲${balance}元。`)
                        console.log('繼續取款請按1,返回上一級就按0')
                        let item2 = readline.question()-0;
                        switch (item2) {
                            case 1:  break;
                                
                            case 0:  flag1=false;
                            
                          
                        }
                    }   
                    break;1

                }
                case 2:
                {   let flag1=true;
                     while(flag1)
                    {
                        console.log(`當前餘額爲${balance}元,請輸入存入金額：`)
                        let savemoney = readline.question()-0;
                        balance+=savemoney;
                        console.log(`取款成功，當前餘額爲${balance}元。`)
                        console.log('繼續存款請按1,返回上一級就按0')
                        let item2 = readline.question()-0;
                        switch (item2) {
                            case 1:  break;
                                
                            case 0:  flag1=false;

                            
                        }
                    }   
                    break;
                } 
                case 3:
                {   
                        console.log(`當前餘額爲${balance}元,請輸入取款金額：`)
                        console.log('返回上一級請按0')
                        let item2 = readline.question()-0;
                        switch (item2) {
                            case 1:  break;
                                
                            case 0:  flag1=false;
                        }
                       
                    break;
                }           
                case 4:
                {
                   console.log('感謝使用！')
                    flag=false;
                    break;
                }
                default:console.log('輸入有誤，請從新輸入：')
            }
        }   
       isGister=true;
        }
}
     if(!isGister)
     {
         
         console.log('登陸失敗，請從新登陸');
         inputfalse++;
         }
   
     if(inputfalse==3)
     {
         console.log('輸入次數過多，鎖卡')
         break;
     }
}