Sizzle class vs tag qualfied class selector (v34)

Revision 34 of this benchmark created by Jeremy Clewell on

Description

Just came across this article http://www.artzstudio.com/2009/04/jquery-performance-rules/ that recommends both tag qualifying class selectors as well as descending from an id for maximum jquery performance. Thought I'd test it out on his examples, because I've learned that you never want to tag qualify ids OR classes if you don't have to (similarly to CSS). However, considering the age of the article, the way jquery works could well be different now.

EDIT: Altered to use Sizzle only.

Preparation HTML

<div id="content" class='container'>
  <form method="post" action="/">
    <h2>Traffic Light</h2>
    <ul id="traffic_light">
      <li><input type="radio" class="on" name="light" value="red" /> Red</li>
      <li><input type="radio" class="off" name="light" value="yellow" /> Yellow</li>
      <li><input type="radio" class="off" name="light" value="green" /> Green</li>
    </ul>
    <input class="button" id="traffic_button" type="submit" value="Go" />
  </form>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/sizzle/2.0.0/sizzle.min.js"></script>

Test runner

Ready to run.

Testing in
TestOps/sec
tag qualified class selector
Sizzle('div.container input.button')
ready
class selector
Sizzle('.container .button')
ready
ID qualified class selector
Sizzle('#content .button')
ready
ID decendant tag qualified class selector
Sizzle('#content input.button')
ready

Revisions

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