原生js实现简易ATM功能

 <script>
        var money = 100;
        var moneySum = 0;
        var num = parseInt(prompt(‘请输入你的操作:‘ + ‘\n‘ +
            ‘1.存钱‘ + ‘\n‘ + ‘2.取钱‘ + ‘\n‘ + ‘3.显示余额‘ + ‘\n‘ + ‘4.退出‘));;
        switch (num) {
            case 1:
                moneySum = parseInt(money) + parseInt(prompt(‘请输入你存钱数‘));
                alert("存款：" + moneySum);
                break;
            case 2:
                var qu = prompt(‘输入你取的钱‘);
                qu = parseInt(qu);
                console.log(qu);

                money = parseInt(money);
                console.log(money);
                if (qu > money) {
                    alert(‘不好意思，钱不够‘)
                } else {
                    alert(‘余额为‘ + (money - qu))
                }
                break;
            case 3:
                alert("余额：" + money);
                break;
            case 4:
                var flag = prompt("是否继续？(Y/N)");
                while (flag !== (‘Y‘ && ‘y‘)) {
                    flag = prompt("是否继续？(Y/N)");
                }
                alert(‘退出成功‘);
                break;
            default:
                alert("输入错误");
                break;
        }
    </script>