标题这是一个表单验证的纯js代码 提供观看 提供了简单的循环语句执行验证操作

执行代码段之前必须含有包文件并且引包！！！！
包文件私我：
包文件名字叫：node_modules
const readline = require(‘readline-sync’);

let user = [['zhangsan', '123'], ['lisi', '124']];
let islog = true;
while (islog) {
    console.log('请输入1.注册2.登陆');
    let opt = readline.question() - 0;
    switch (opt) {
        case 1://注册
            {
                console.log('请输入您的账号');
                let usname = readline.question();
                let isLogin = false;
                for (let item of user) {
                    if (usname == item[0]) {
                        isLogin = true;
                        console.log('账号不可使用');
                        break;
                    }
                }
                if (!isLogin) {
                    console.log('请输入您的密码');
                    let Pwd = readline.question();
                    user.push([usname, Pwd]);
                    console.log('恭喜注册成功');

                }
                break;
            }
        case 2://登陆
            {
                console.log('请输入您的账号');
                let usname = readline.question();
                console.log('请输入您的密码');
                let Pwd = readline.question();
                let flage = false;
                for (let item of user) {
                    if (item[0] == usname && item[1] == Pwd) {
                        console.log('登陆成功');
                        flage = true;
                        islog = false;
                        break;
                    }
                }
                if (!flage) {
                    console.log('查无此人');
                }
                break;
            }
    }
    
}