title: Php Replace in string Preg_match
body: <p>I want to check in wp if post content  includes gx-block class.<br>
  For example I can have  </p>
  
  <pre><code>class="something_can_exists_or_not gx-block something_else" should print *true*
  
  class="gx-block" *true*
  Etc.
  </code></pre>
  
  <p>I have  tried  this but doesn't work  </p>
  
  <p><code>preg_match('/class="?.*gx-block?.*"/i', $content);</code></p>
  
  <p>Thanks</p>