Info

Curious to see if there is any perf diff between querySelectorAll('.cat.bobtail') and querySelectorAll('[data-cat="bobtail"]'), because I would rather use more meaningful data- attribute than some arbitrary class names.

Preparation code

<section id="test">
</section>
<script>
  Benchmark.prototype.setup = function() {
    var section = document.getElementById('test');
    for (var i = 0; i < 500; i++) {
      var div = document.createElement('div');
      if (i % 3 === 0) {
        div.className = 'foo bar';
        div.dataset.foo = 'bar';
      } else {
        div.className = 'foo poo';
        div.dataset.foo = 'poo';
      }
    
      section.appendChild(div);
    }
  };
</script>

Preparation code output

Test runner

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Java applet disabled.

document.querySelectorAll('.foo.bar');

document.querySelectorAll('[data-foo="bar"]');

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Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL. Here’s a list of current revisions for this page:

• Revision 1: published by girlie_mac on 30th December 2012
• Revision 2: published by Jim Montgomery on 11th January 2013
• Revision 3: published by Jim Montgomery on 14th January 2013

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