使用正则表达式进行Javascript密码验证

Question

I have a problem with my password validation using regex on javascript. the criteria are :

1. have at least one or more letter(it can be upper case or lower case)
2. have at least one or more number
3. character length minimal 3 and maximal 30

I hope anyone can help me to solve this problem :)

var ch_pass = /^([0-9]+).([a-zA-Z]+).({3,30})$/;

Answer 1

您可以像这样使用前瞻：

var ch_pass = /^(?=.*?[0-9])(?=.*?[a-zA-Z]).{3,30}$/;

Answer 2

I wouldn't recommend trying to do this whole check in a single regular expression because it just over complicates it. Do each condition individually.

1. Has at least one letter:

    var has_letters = (/[a-zA-Z]/).test(password); 

2. Has at least one number:

    var has_numbers = (/[0-9]/).test(password); 

3. Has between 3 and 30 characters (inclusive):

    var has_length = 3 <= password.length && password.length <= 30; 

This can all be wrapped up into a function:

function is_password_valid(password) {
    var has_letters = (/[a-zA-Z]/).test(password);
    var has_numbers = (/[0-9]/).test(password);
    var has_length = 3 <= password.length && password.length <= 30;
    return has_letters && has_numbers && has_length;
}

Or if you prefer something more dense:

function is_password_valid(password) {
    return ((/[a-zA-Z]/).test(password)
        && (/[0-9]/).test(password)
        && password.length >= 3
        && password.length <= 30);
}