Help needed in Regular Expression

See below article you will find solution yourself

The 30 Minute Regex Tutorial[^]

You should make an effort to learn more about Regular Expressions. A good place to get started is here. Another very helpful site is regexlib[^]; they have a large library of Regular Expressions. They also have a RegEx tester[^]. Also a very useful RegEx tool is available here.

Hi Rashmi
it may be help you...
[0-9]{0,6}[-]{1}[0-9]{0,7}[a-zA-Z]{0,1}



Thank u
Gaja

The following regular expression pattern can be used for this purpose.

(?=^[a-zA-Z0-9]{5}-[a-zA-Z0-9]{6}$)(?=(?:\d*[a-zA-Z]?\d*-\d*|\d*-\d*[a-zA-Z]?\d*)).*

In this pattern the (?=^[a-zA-Z0-9]{5}-[a-zA-Z0-9]{6}$) will look ahead to sea that the string contains 5-6 alphanumeric digits.

Then (?=(?:\d*[a-zA-Z]?\d*-\d*|\d*-\d*[a-zA-Z]?\d*)) looks ahead to see if there is either one or none alphabet in the string. If the above two tests succeed then the string is matched.

It can be tested here
http://regexhero.net/tester/[^]

Guessing from your question, I unerstand that you have groups of 5 to 6 digits, plus mixed in some single a-z characters (none or one per group).

If you have to only take these groups that match your constraints (at most one [a-z] in a group), then I have the following solution:

string pattern = @"\b[0-9][0-9][0-9][0-9][0-9][0-9a-z]?\b"
              + @"|\b[a-z][0-9][0-9][0-9][0-9][0-9]?\b"
              + @"|\b[0-9][a-z][0-9][0-9][0-9][0-9]?\b"
              + @"|\b[0-9][0-9][a-z][0-9][0-9][0-9]?\b"
              + @"|\b[0-9][0-9][0-9][a-z][0-9][0-9]?\b"
              + @"|\b[0-9][0-9][0-9][0-9][a-z][0-9]?\b"
              ;

This may look silly, but I don't come up with a better solution for the above stated problem. The issue is that you can not count how often a pattern was matched before (e.g. the [a-z]).

Cheers
Andi