使用setCustomValidity在javascript中进行正则表达式验证

Question

 var ck_login = new RegExp("/^[a-zA-Z]{5,12}$/"); var ck_password = new RegExp("/^(?=.*\\d)(?=.*[az]).{6,16}$/"); function validate(){ var login = document.getElementById("login").value; var loginErr = document.getElementById("login"); var password = document.getElementById("password").value; var passwordErr = document.getElementById("password"); if (ck_password.test(password) == false) { passwordErr.setCustomValidity('Password must have at least 6 characters at least no more than 16. At least one low and one number'); return false; } if (ck_login.test(login) == false) { loginErr.setCustomValidity('Login must have at least 5 characters and no more than 12'); return false; } return true; } 

 <form action="" method="post" onSubmit="return validate();"> <label>Username:</label> <input type="text" name="login" id="login" required="required"> <label>Password:</label> <input type="text" name="password" id="password" required="required"> <input type="submit"> </form> 

I am trying to do form validations where Login must have at least 5 characters and no more than 12 and Password must have at least 6 characters at least no more than 16. At least one low and one number.

Regex is correct but it's not working in javascript properly. I can't find what mistake I am doing.

Thanks.

Answer 1

Do not create regular expressions using the RegExp constructor.

Do it like this:

var ck_login = /^[a-zA-Z]{5,12}$/;
var ck_password = /^(?=.*\d)(?=.*[a-z]).{6,16}$/;

If you are going to use the RegExp constructor, don't use slashes at the beginning-end of the string.

var ck_login = new RegExp("^[a-zA-Z]{5,12}$");
var ck_password = new RegExp("^(?=.*\d)(?=.*[a-z]).{6,16}$");