Need to change my Regular expression for special characters

Question

0.00/5 (No votes)

See more:

I need to have a regular expression to check if the password has atleast one character and one special character anywhere in the password. Hence i used the below regular expression,

C#

if (!System.Text.RegularExpressions.Regex.IsMatch(a, "^(?=.*[#@].*)(?=.*[a-zA-Z].*)[a-zA-Z0-9#@]{6,15}$"))
{...}

But this regular expression doesnot allow the special character to be last of the password. Say for example, it allows test!6767 but it doesnot allow test6767!.

Please tell me what i change i should do in the external expression

Thanks

Posted 13-Sep-11 5:55am

sri_3464

Updated 13-Sep-11 6:17am

v2

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Simon Bang Terkildsen · Answer 1 · 2011-09-13T06:05:00

Solution 1

From my answer to the question How to verify a password which contain .......[^]

(?=^.{8})(?=.*[a-z])(?=.*[A-Z])(?=.*[^\w\d])(?=.*\d).*$

(?=^.{8})
The minimum length

(?=.*[a-z])
Verify atleast one lowercase character

(?=.*[A-Z])
Verify atleast one uppercase character

(?=.*[^\w\d])
Verify atleast one special character

(?=.*\d)
Verify atleast one digit

Posted 13-Sep-11 6:05am

Simon Bang Terkildsen

Updated 13-Sep-11 6:09am

v3

Comments

Simon Bang Terkildsen 13-Sep-11 12:18pm

OP wrote
For the special character check my regular expression works too and so is your solution. But my issue is when the special character is at the last of the password then validation fails. Say if password is test!6767 then it validates as correct password. But when the password is test6767! it says as wrong password. But it is not.

Simon Bang Terkildsen 13-Sep-11 12:22pm

I've just tested your regex and you state that it matches test!6767.. It does NOT. You specifically state which special characters you allow and you do NOT allow !
Which is also why it doesn't match test6767!

Simon Bang Terkildsen 13-Sep-11 12:20pm

Yeah I get that you've written your regex that works and then not entirely, my answer was not supposed to be a "here is the solution to all your problems"-answer but to allow you to find your mistake yourself.