title: How to extract Heading tags in PHP from a string?
body: <p>From a string that contains a lot of HTML, how can I extract all the text from <code>&lt;h1&gt;&lt;h2&gt;etc</code> tags into a new variable?</p>
  
  <p>I would like to capture all of the text from these elements and store them in a new variable as comma-delimited values.</p>
  
  <p>Is it possible using <code>preg_match_all()</code>?</p>