Regex Javascript

Question

I am using the below regex in JavaScript for password policy check:

^.*(?=.{8,})(?=.*[a-z])(?=.*[A-Z])(?=.*[0-9])(?=.*[@#$_])(?=.*[\d\W]).*$

I tried the above regex using online regex checker http://www.nvcc.edu/home/drodgers/ceu/resources/test_regexp.asp

Test cases passed as expected, negative test cases failed. But same regex when deployed in application does not validate properly.

For eg: Tracker@123 does not work, where tRacker@123 works Asd56544#12 also works fine.

Can you please point out what's wrong in regex above?

um, all 3 of your test cases pass for me (as they should). Can you post your code that says it's failing? — user578895
– user578895, Commented May 11, 2011 at 7:50
It seems to work, maybe the problem is in the way you use it — Riccardo Galli
– Riccardo Galli, Commented May 11, 2011 at 7:55
what's the point in the leading .* or the last group (?=.*[\d\W])? (not that it's your problem) — user578895
– user578895, Commented May 11, 2011 at 7:55

Eugene · Accepted Answer · 2011-05-11 08:01:46Z

1

My advice is to separate this regex into several simple regex'es. You may assign rules for your password, and for every rule you can assign a regex.

For example

Rule №1. Minimal length of password = 8 characters (can be done without regex)
Rule №2. At least one digit is required. ( /[0-9]/ )
Rule №3. At least one letter is required ( /[a-z]/i)
Rule №4. Illegal characters for password ( regex for some characters you don't want users to use in passwords)
Rule №n - some little regex

(and so on)

With this approach, it will be more easier to manage your validation in sooner time. For example after a year, you'll have to change your password policy. You'll forget what your big regex is meaning (and will spend a lot of time changing that big regex, or doing a new one). But with little separates regexes (meaning rules) you easily configure your password policy

answered May 11, 2011 at 8:01

Eugene

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2 Comments

user632323 Over a year ago

Thanks all for your hints and responses. I removed the last part (?=.*[\d\W]) and things started working fine. Why is that i should not sepcify \d or \W ?

Eugene Over a year ago

2 user632323: What did you want to do by adding (?=.*[\d\W]) ? It means "any symbols before a digit or not a word"

David · Accepted Answer · 2011-05-11 07:54:33Z

0

Are you sure you syntax is correct?

Have a look at this JSfiddle, in it all the test cases pass

http://jsfiddle.net/pCLpX/

answered May 11, 2011 at 7:54

David

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