How to extract a substring from a .NET RegEx?

Question

I have an XML file containing one (or more) key/value pairs. For each of these pairs I want to extract the value which is a two-byte hex value.

So the XML contains this snippet:

<key>LibID</key><val>A67A</val> 

Which I can match using the following expression, with the ID in parenthesis.

Match match = Regex.Match(content, @"<key>LibID</key><val>([a-fA-F0-9]{4})</val>");  if (match.Success) {   Console.WriteLine("Found Match for {0}\n", match.Value);   Console.WriteLine("ID was {0}\n", "Help me SO!"); } 

How can I change the last part so it returns the ID from the match?

Cheers!

Answer 1

I think you want

match.Groups[1].Value 

(As Dillie-O points out in the comments, it's group 1 because group 0 is always the whole match.)

Short but complete test program:

using System; using System.Text.RegularExpressions;  class Program {   static void Main()   {     Regex regex = new Regex("<key>LibID</key><val>([a-fA-F0-9]{4})</val>");     Match match = regex.Match("Before<key>LibID</key><val>A67A</val>After");      if (match.Success)     {       Console.WriteLine("Found Match for {0}", match.Value);       Console.WriteLine("ID was {0}", match.Groups[1].Value);     }         } } 

Output:

Found Match for <key>LibID</key><val>A67A</val> ID was A67A