Info

Is it faster to remove an item from an array (and thus allow the indices to be renumbered) or delete a property from an object. Also, checking deletion from array, but this does not renumber the indices so may not be preferable.

Preparation code

<script>
  var count = 100000;
  var deleteInc = 100;
</script>
<script>
  Benchmark.prototype.setup = function() {
      var someArr = [];
      var someObj = {};
      for(var i = 0; i < count; i++)
      {
        someArr[i] = Math.floor(Math.random() * 1000000);
        someObj['a' + i] = Math.floor(Math.random() * 1000000);
      }
    
  };
</script>

Test runner

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for(var i = 0; i < count; i += deleteInc)
{
    someArr.splice(i, 1);
}

for(var i = 0; i < count; i += deleteInc)
{
    delete someObj['a' + i];
}

for(var i = 0; i < count; i += deleteInc)
{
    delete someArr[i];
}

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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 on 3rd April 2011
• Revision 2: published on 20th June 2012
• Revision 3: published by Quentin Brooks on 18th November 2012
• Revision 4: published on 17th February 2013
• Revision 5: published on 20th February 2013
• Revision 6: published by Reuven on 6th March 2013
• Revision 7: published on 22nd May 2013
• Revision 9: published 5 days ago

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