Array Performance 42

JavaScript performance comparison

Revision 31 of this test case created


Manual array lookups vs. holey arrays.

Preparation code

  Benchmark.prototype.setup = function() {
    var a1 = [{id: 32994, name: 'name1'}, {id: 29938, name: 'name1'}];

    var a2 = [];
    a2[29938] = {id: 29938, name: 'name1'};
    a2[32994] = {id: 32994, name: 'name1'};

    var o = {};
    o[29938] = {id: 29938, name: 'name1'};
    o[32994] = {id: 32994, name: 'name1'};

Test runner

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Testing in unknown unknown
Test Ops/sec
Manual Array Lookup
var id = 29938;
for (var i = 0; i < a1.length; i++) {
  if (a1[i].id = id) result = a1[i];
Holey Array by Index
var id = 29938;
var result = a2[id];
Object by Key
var id = 29938;
var result = o[id];

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