getElementById vs. querySelector

JavaScript performance comparison

Revision 32 of this test case created by

Preparation code

<p id="foo">Foo</p>
<p id="bar">Bar</p>
<p id="baz">Baz</p>

<p class="test">Baz</p>

<p class="test">Baz</p>
<p class="test">Baz</p>


<p class="test">Baz</p>
      
<script>
Benchmark.prototype.setup = function() {
  var select = function(name)
  {
      var o = name.charAt(0);
      if      (o == '#') return document.getElementById(name.substr(1, name.length -1));
      else if (o == '.') return document.getElementsByClassName(name.substr(1, name.length -1));   
      else               return document.getElementsByTagName(name); 
  }; 

};
</script>

Preparation code output

<p id="foo">Foo</p> <p id="bar">Bar</p> <p id="baz">Baz</p> <p class="test">Baz</p> <p class="test">Baz</p> <p class="test">Baz</p> <p class="test">Baz</p>

Test runner

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Java applet disabled.

Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
getElementById
var bar = document.getElementsByClassName(".test");
pending…
querySelector
var bar = document.querySelectorAll(".test");
pending…
mapping to getElementById
var bar = select(".test");
pending…

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Revisions

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