Regular Expression

Question

Hi

I am working in asp.net. I am using Regular Expression Validator

Could you please help me in creating a regular expression for not allowing special characters other than comma. Comma has to be allowed.

I checked in regexlib, however I could not find a match. I treid with "^(a-z|A-Z|0-9)*[^#$%^&*()']*$" . When I add other characters as invalid, it does not work.

Also could you please suggest me a place where I can find a good resource of regular expressions? regexlib seems to be big; but any other place which lists very limited but most used examples?

Also, can I create expressions using C# code? Any articles for that?

Anyway, my immediate requirement is the special character problem

Thanks Lijo

Answer 1

For a single character that is not a comma, [^,] should work perfectly fine.

Answer 2

[\d\w\s,]*

Just a guess

Answer 3

Hi Lijo,

You can try [\w\s,] regular expression. This regex will match only alpha-numeric characters and comma. If any other character appears within text, then this wont match.

For your second question regarding regular expression resource, you can goto

http://www.regular-expressions.info/

This website has lot of tutorials on regex, plus it has lot of usefult information.

Also, can I create expressions using C# code? Any articles for that?

By this, do you mean to say you want to know which class and methods for regular expression execution? Or you want tool that will create regular expression for you?

Answer 4

[\w\s,]+

works fine, as you can see bellow.

RegExr is a great place to test your regular expressions with real time results, it also comes with a very complete list of common expressions.

[] character class \w Matches any word character (alphanumeric & underscore). \s Matches any whitespace character (spaces, tabs, line breaks). , include comma + is greedy match; which will match the previous 1 or more times.

Answer 5

You can create expressions with C#, something like this usually does the trick:

        Regex regex = new Regex(@"^[a-z | 0-9 | /,]*$", RegexOptions.IgnoreCase);
        System.Console.Write("Enter Text");
        String s = System.Console.ReadLine();
        Match match = regex.Match(s);
        if (match.Success == true)
        {
            System.Console.WriteLine("True");
        }

        else
        {
            System.Console.WriteLine("False");
        }
        System.Console.ReadLine();

You need to import the System.Text.RegularExpressions; The regular expression above, accepts only numbers, letters (both upper and lower case) and the comma.

For a small introduction to Regular Expressions, I think that the book for MCTS 70-536 can be of a big help, I am pretty sure that you can either download it from somewhere or obtain a copy.

I am assuming that you never messed around with regular expressions in C#, hence I provided the code above.

Hope this helps.

Answer 6

Thank you, all..

[\w\s,]* works

Let me go through regular-expressions.info and come back if I need further support.

Let me try the C# code approach and come back if I need further support.

[This forum is awesome. Quality replies so qucik..]

Thanks again

Answer 7

One more question... What if I should not allow space also? I tried with "[\w,]*". It works fine if I am entering space aftere a character. If I enter space first, it does not work. Please help

Answer 8

(…) is denoting a grouping and not a character set that’s denoted with […]. So try this:

^[a-zA-Z0-9,]*$

This will only allow alphanumeric characters and the comma.