title: get tagname in xml using php
body: <p>Here is my xml:</p>
  
  <pre><code>&lt;news_item&gt;    
      &lt;title&gt;TITLE&lt;/title&gt;
      &lt;content&gt;COTENT.&lt;/content&gt;
      &lt;date&gt;DATE&lt;/date&gt;
  &lt;news_item&gt;
  </code></pre>
  
  <p>I want to get the names of the tags inside of news_item.</p>
  
  <p>Here is what I have so far:</p>
  
  <pre><code>$dom = new DOMDocument();
  $dom-&gt;load($file_name);
  $results = $dom-&gt;getElementsByTagName('news_item');
  </code></pre>
  
  <p><strong>WITHOUT USING other php libraries like simpleXML</strong>, can I get the name of all the tag names (not values) of the children tags?</p>
  
  <p>Example solution</p>
  
  <pre><code>title, content, date
  </code></pre>
  
  <p>I don't know the name of the tags inside of news_item, only the container tag name 'news_item'</p>
  
  <p>Thanks guys! </p>