Performance of Array vs. Object (v148)

Revision 148 of this benchmark created by iProDev on

Description

After seeing http://jsperf.com/javascript-associative-vs-non-associative-arrays, I thought the test could be improved.

Preparation HTML

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>

Setup

var arr = [],
        arrHoles = [],
        i,
        obj = {};
    for(i = 0; i < 10000; i += 1) {
        var o = {payload:i};
        arr.push(o);
        obj[i] = o;
    }
    arrHoles[9999] = {payload:9999};
    var keys = Object.keys(obj);
    var arrLength = arr.length;
    var keysLength = keys.length;

Test runner

Ready to run.

Testing in
TestOps/sec
Array Performance
var sum = 0;
for (var x=0; x<arrLength; ++x) {
    sum += arr[x].payload
}
ready
Object Performance
var sum = 0;
for (var x in obj) {
    sum += obj[x].payload;
}
ready
Object Performance using known length
var sum = 0;
for (var x=0; x<10000; x++) {
    if(obj[x] !== undefined) {
      sum += obj[x].payload
    }
}
ready
Using Object.keys()
var sum = 0;
for (var x=0; x < keysLength; x++) {
    sum += obj[keys[x]].payload
}
ready
Array with holes
var sum = 0;
for (var x=0; x<arrHoles.length; ++x) {
    if(arrHoles[x]) {
       sum += arrHoles[x]
    }
}
ready
Array with holes undefined check
var sum = 0;
for (var x=0; x<arrHoles.length; ++x) {
    if(arrHoles[x] !== undefined) {
       sum += arrHoles[x]
    }
}
ready
$.each
var sum = 0;
$.each(obj, function(key, value){
    sum += value.payload
})
ready

Revisions

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