jQuery.unique VS _.uniq Performance

JavaScript performance comparison

Test case created by EtnasSoft on 22nd February 2013 and last updated on 25th February 2013

Preparation code

<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.4.4/underscore-min.js"></script>
<script>
  Benchmark.prototype.setup = function() {
    var $ = window.$;
    var _ = window._;
    var myArr = [1, 2, 1, 3, 1, 4];
  };
</script>

Preparation code output

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Testing in unknown unknown
Test		Ops/sec
jQuery	`var result = $.unique( myArr );`	pending…
Underscore	`var result = _.uniq( myArr );`	pending…

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Revisions

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Revision 1: published by EtnasSoft on 22nd February 2013 and last updated on 25th February 2013
Revision 2: published on 22nd February 2013

1 comment

gnz / vnk commented on 22nd February 2013: ∞

Kind of like comparing apples to bacon, isn't it? The jQuery documentation states:

jQuery.unique( array ) Returns: Array

Description: Sorts an array of DOM elements, in place, with the duplicates removed. Note that this only works on arrays of DOM elements, not strings or numbers.

(emphasis mine)

And then if one dived into the code, one could see that unique, like some of the stuff in jQuery, is simply wrongly named and does actually something very different. jQuery.unique is actually all about sorting. About sorting in document order. And then also, as an additional service, removing duplicates.