Array Performance

JavaScript performance comparison

Revision 55 of this test case created


Manual array lookups vs. holey arrays.

Preparation code

  Benchmark.prototype.setup = function() {
    var a1 = [];
    var 0 = {};
    for (var i=0;i<33000;++i){
        a1.push({id:i, name:"name1"});
        o[i] = {id:i, 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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