title: Unrecognized escape sequence \_. C# regex
body: <p>I have the following regex which is working ok in <a href="https://regex101.com/" rel="nofollow noreferrer">https://regex101.com/</a> and so I want to use it in C# but I get the error <code>Unrecognized escape sequence \_</code>.</p>
  
  <pre><code>^https:\/\/github\.com\/([a-zA-Z\-0-9]+)\/([a-zA-Z\-\_]+)\/commit\/([a-fA-F0-9]{40}),(.*),([0-9]+),([0-9]+)$
  </code></pre>
  
  <p>in C# I do that:</p>
  
  <pre><code>string regex = @"^https:\/\/github\.com\/([a-zA-Z\-0-9]+)\/([a-zA-Z\-\_]+)\/commit\/([a-fA-F0-9]{40}),(.*),([0-9]+),([0-9]+)$";
  </code></pre>
  
  <p>and then want to do:</p>
  
  <pre><code>if (Regex.IsMatch(input, regex)) and so on. the error is here on that line.
  </code></pre>
  
  <p>I cant understand why I get the error in case I use <code>@</code></p>