title: JQuery: how to access multiple css classes using .attr()?
body: <p>I have the following:</p>
  
  <pre><code>&lt;div id="unique" class="myclass xyz_345"&gt;...&lt;/div&gt;
  </code></pre>
  
  <p><strong>Question</strong>: How do I access what # is after <code>xyz_</code>, given that I have 2 css classes being applied to it? (In the example above, it would be the number 345).</p>
  
  <p>I've tried the following, but it does work:</p>
  
  <pre><code>var num_after_xyz = $('unique').attr("class").substring(4);
  </code></pre>