Regular expression to allow either number or special characters

Question

I have a regex to allow characters, atleast one number and special character text limit 8 to 15..

function validatePassword(password) {
    var re = /^(?=.*[A-Za-z])(?=.*\d)(?=.*[$@.$!%*#?&])[A-Za-z\d$@.$!%*#?&]{8,15}$/i;
    return re.test(password);
}

Now I need to change this regex to accept either one number or one special character and same 8 to 15 limit

Answer 1

You need to remove the lookahead requiring a digit, and move the \d to the lookahead requiring a special character:

var re = /^(?=.*[A-Za-z])(?=.*[\d$@.!%*#?&])[A-Za-z\d$@.!%*#?&]{8,15}$/;
                               ^^

If you do not need to require at least one letter, remove (?=.*[A-Za-z]).

Details:

• ^ - start of string
• (?=.*[A-Za-z]) - there must be at least 1 ASCII letter
• (?=.*[\d$@.$!%*#?&]) - there must be at least 1 digit, or any one of the special chars in the class
• [A-Za-z\d$@.!%*#?&]{8,15} - the string should only consist of letters, digits, and the special chars listed, from 8 to 15 occurrences.
• $ - end of string.

Note that once you are using a-zA-Z, you do not need the /i case insensitive modifier.

Also, no ned to repeat $ in one and the same character class.