title: jQuery selector performance difference
body: <p>What is the difference between those 2 selectors? Can I use second one in order to optimize my scripts?</p>
  
  <pre><code>$('#'+idTest);  
  jQuery(document.getElementById(idTest));  
  </code></pre>
  
  <p>According to my test on <a href="http://jsperf.com/jquery-selector-speeds/4" rel="nofollow">http://jsperf.com/jquery-selector-speeds/4</a> , second one is 3 times faster (comparing <code>1,026,651 [Ops/sec]</code> with second one <code>3,778,351 [Ops/sec]</code>).</p>