title: PHP: No match when using exclamation mark in regular expression
body: <p>I'm trying to use preg_match to find a commented part in a loaded HTML file. The exclamation mark present seems to break it, however. Whenever I try to use</p>
  
  <pre><code>preg_match("/&lt;!/", "&lt;!", $matches);
  </code></pre>
  
  <p>an empty $matches[0] is returned. I've tried</p>
  
  <pre><code>preg_match("/&lt; !/", "&lt; !", $matches);
  preg_match("/!&lt;/", "!&lt;", $matches);
  </code></pre>
  
  <p>and these do return "&lt; !" and "!&lt;". I've searched everywhere for a solution, but I can't seem to find a solution for this most likely very easy-to-solve problem.</p>
  
  <p>Thanks in advance.</p>