JQuery $('#id') selector vs $(document.getElementById('id')

JavaScript performance comparison

Revision 10 of this test case created

Info

Fastest way get a jQuery object of a DOM element of which I have the ID. document.getElementById has the advantage of not requiring escaping for special characters.

Preparation code

<div id="el">
  Some HTML element
</div>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js">
</script>
<script>
  var el = document.getElementById('el'),
      did = 'el',
      jid = '#el';

  function S4() {
    return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
  }
</script>
<script>
  Benchmark.prototype.setup = function() {
    el.id = did = S4();
    jid = '#' + did;
  };
</script>

Preparation code output

Some HTML element

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Testing in unknown unknown
Test Ops/sec
jQuery('#id')
 
jQuery(jid).length;
 pending…
document.getElementById('id')
 
document.getElementById(did);
 pending…

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