title: C# If regex doesn't match then do something
body: <p>So I got piece of code, which works like if someone writes in chat !buy 3, then Regex gets that number 3 and does stuff, but how could I make code that if someone just types !buy, then it tells "him" something, else than throwing error to console because there were no number.</p>
  
  <pre><code>var getinfo = message.ToString();
  Regex getInfo = new Regex("[0-9]+");
  var random3 = getInfo.Match(getinfo).Value;
  </code></pre>