concat vs push.apply

JavaScript performance comparison

Revision 19 of this test case created by Kevin Ennis

Preparation code

<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
 
<script>
  Benchmark.prototype.setup = function() {
    var sampleA = [],
        sampleB = [],
        core_push = Array.prototype.push;
    
    for (var i = 0; i < 42; ++i) {
      sampleA[i] = {};
      sampleB[i] = {};
    }
  };
</script>

Preparation code output

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Testing in unknown unknown
Test Ops/sec
concat
 
var cloneA = sampleA.slice(0);
var cloneB = sampleB.slice(0);

cloneA = cloneA.concat(cloneB);
 pending…
push.apply
 
var cloneA = sampleA.slice(0);
var cloneB = sampleB.slice(0);

cloneA.push.apply(cloneA, cloneB);
 pending…
Array#push.apply
 
var cloneA = sampleA.slice(0);
var cloneB = sampleB.slice(0);

Array.prototype.push.apply(cloneA, cloneB);
 pending…
core_push.apply
 
var cloneA = sampleA.slice(0);
var cloneB = sampleB.slice(0);

core_push.apply(cloneA, cloneB);
 pending…
$.extend
 
var cloneA = sampleA.slice(0);
var cloneB = sampleB.slice(0);

$.extend(cloneA, cloneB);
 pending…

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Revisions

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1 comment

Kevin Ennis commented : ∞

The older versions of this test were actually mutating the original sampleA and sampleB arrays when they ran - which totally invalidates the results.

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