Array Performance

JavaScript performance comparison

Revision 54 of this test case created

Info

Manual array lookups vs. holey arrays.

Preparation code

<script>
    function ArrayItem(id) {
        this.id = id;
        this.name = 'name' + id;
    }
  Benchmark.prototype.setup = function() {
    var a1 = [];
    var o = {};

   for (var i=0; i<100; i++)
{
  var pItem1 = new ArrayItem(i);
  var pItem2 = new ArrayItem(i);
  a1.push(pItem1);
  o[i] = pItem2;
}
    var a2 = [];
    a2[50] = {id: 50, name: 'name1'};
    a2[99] = {id: 99, name: 'name2'};

  };
</script>

Test runner

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Testing in unknown unknown
Test Ops/sec
Manual Array Lookup
var id = 50;
for (var i = 0; i < a1.length; i++) {
  if (a1[i].id = id) result = a1[i];
}
 
pending…
Holey Array by Index
var id = 50;
var result = a2[id];
pending…
Object by Key
var id = '50';
var result = o[id];
 
pending…

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