Can regexes capture a substring without using groups?

Question

The regex foo/(\w*)/bar matches the string foo/123/bar.

This is probably something basic that I've missed about regexes, but often I only want to retrieve the substring between the slashes. Is there a simple .NET API I can use without having to access the groups collection? Or an alternative way of writing the regex?

Thanks!

Answer 1

The short answer is no, but it really is no hassle to get the capture:

string cap = Regex.Match(inputString, @"foo/(\w*)/bar").Groups[1].ToString();

Answer 2

It is possible using lookaround:

(?<=foo/)\w*(?=/bar) 

applied to foo/123/bar. matches "123". Groups are a better method and bear in mind that lookaround (in particular look behind) is not supported in all regex tools, but it is in .net.

note: \w is shorthand for a character class, you don't need to put it inside []

Answer 3

If the string is guaranteed to be matched, and you only want the substring between the two slashes, String.Split can be used instead of Regular Expression:

String sub = str.Split('/')[1]