title: Search class for specific text and return entry number
body: <p>I have a kind of unique need of finding one <code>div</code> on all divs with same class name that has a specific copy, and return the entry number:</p>
  
  <pre><code>&lt;div class="alertme"&gt;&lt;/div&gt;
  &lt;div class="alertme"&gt;&lt;/div&gt;
  &lt;div class="alertme"&gt;This text&lt;/div&gt;
  &lt;div class="alertme"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>So it would return 2, being 0 is the first <code>div</code>.</p>