Question

I have a string I need to split using a Regex. I could use the split methods in .NET but the string to return could be the first or second substrings. This regex will become a configurable setting in an application.

A typical string would be 9234567X123456-789

I’ve create the following regex

     [-09]([^X]*)X

to return the first substring. However, I lose the first digit, 234567 is returned.

Any ideas?

Thanks.

Answer 1

I’m assuming that you want the string to start with either -, 0 or 9. If this is true the regex you need (and using regexes here is overkill unless you want to also perform a sort of validation) is

([-09]\d*)X

OR

([-09][^X]*)X

if you are allowing any kind of character (not only digits) in the part before the X

EDIT:

Might have understood what you are looking for reading your sample string:

9234567X123456-789

You need either the first or the second group and every group can have digits or hypen (-). You solve this by creating two groups:

([\d\-]+)X([\d\-]+)

then you can check Jon Skeet’s answer to get the data. You could either use

match.Groups[1]); //to get 9234567

or

match.Groups[2]); //to get 123456-789