Regex for multiple matches .net c#

Question

I'm workin on a regex:

Regex regex = new Regex(@"(?<=[keyb])(.*?)(?=[\/keyb])");

With this regex im gettig everything between tags [keyb] and [/keyb]

example: [keyb]hello budy[/keyb]

output: hello buddy

What about if I want to get everything between [keyb][/keyb] and also [keyb2][/keyb2]?

example: [keyb]hello budy[/keyb] [keyb2]bye buddy[/keyb2]

output: hello buddy

bye buddy

Answer 1

Use

\[(keyb|keyb2)]([\w\W]*?)\[/\1]

See regex proof .

EXPLANATION

--------------------------------------------------------------------------------
  \[                       '['
--------------------------------------------------------------------------------
  (                        group and capture to \1:
--------------------------------------------------------------------------------
    keyb                     'keyb'
--------------------------------------------------------------------------------
   |                        OR
--------------------------------------------------------------------------------
    keyb2                    'keyb2'
--------------------------------------------------------------------------------
  )                        end of \1
--------------------------------------------------------------------------------
  ]                        ']'
--------------------------------------------------------------------------------
  (                        group and capture to \2:
--------------------------------------------------------------------------------
    [\w\W]*?                 any character of: word characters (a-z,
                             A-Z, 0-9, _), non-word characters (all
                             but a-z, A-Z, 0-9, _) (0 or more times
                             (matching the least amount possible))
--------------------------------------------------------------------------------
  )                        end of \2
--------------------------------------------------------------------------------
  \[                       '['
--------------------------------------------------------------------------------
  /                        '/'
--------------------------------------------------------------------------------
  \1                       what was matched by capture \1
--------------------------------------------------------

C# code :

using System;
using System.Text.RegularExpressions;

public class Example
{
    public static void Main()
    {
        string pattern = @"\[(keyb|keyb2)]([\w\W]*?)\[/\1]";
        string input = @" [keyb]hello budy[/keyb] [keyb2]bye buddy[/keyb2]";
        RegexOptions options = RegexOptions.Multiline;
        
        foreach (Match m in Regex.Matches(input, pattern, options))
        {
            Console.WriteLine("Match found: {0}", m.Groups[2].Value);
        }
    }
}

Results :

Match found: hello budy
Match found: bye buddy

Answer 2

var pattern=@"\[keyb.*?](.+?)\[\/keyb.*?\]";