Limit chars occurrences with regex

Question

I'm using for exmaple this simple regex:

([A-Za-z0-9!@#]*)

I want to limit the chars !, @ and #, while each of them can appear up to 5 times in the whole string.

Valid strings will be: t!!!sd###ui##pp!@, !@#II#@!00!! etc.

Not valid strings will be: 3!222@34@#@@#@@@!, !@!@!@!@!@!A

Is it possible?

http://stackoverflow.com/questions/1649435/regular-expression-to-limit-number-of-characters-to-10 — adifire, Feb 09 '14 at 13:01

score 1 · Answer 1 · answered Feb 09 '14 at 13:05

1

You can use this pattern:

^(?!(?:[^!]*!){6})(?!(?:[^@]*@){6})(?!(?:[^#]*#){6})[A-Za-z0-9!@#]*$

answered Feb 09 '14 at 13:05

anubhava · Answer 2 · 2014-02-10T03:26:06.227

0

You need to use lookahead for this. Use this regex:

^(?!(.*?!){6})(?!(.*?#){6})(?!(.*?@){6})[A-Za-z0-9!@#]+$

edited Feb 10 '14 at 03:26

answered Feb 09 '14 at 13:01

anubhava

`a@sd@@@@!` returns false, while it should be true. – Opu Feb 09 '14 at 13:04
Let me test and revert back. – anubhava Feb 09 '14 at 13:06
@nhahtdh: Thanks for your comment. I had a typo (closing bracket misplaced). Corrected now, it should work now. – anubhava Feb 10 '14 at 03:27

2 Answers2