title: jQuery .hasClass() vs .is()
body: <p>is there a preferred method of determining whether an element is assigned a class, from a performance standpoint?</p>
  
  <pre><code>$('#foo').hasClass('bar');
  </code></pre>
  
  <p>or</p>
  
  <pre><code>$('#foo').is('.bar');
  </code></pre>