Performance of Array vs. Object (v191)

Revision 191 of this benchmark created 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 = [],
        i,
        obj = {};
    for(i = 0; i < 10000; i += 1) {
        var o = {payload:i};
        arr.push(o);
        obj[i] = o;
    }

Test runner

Ready to run.

Testing in
TestOps/sec
Array Performance
var sum = 0;
var length = arr.length;
for (var x=0; x<length; ++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) {
    sum += obj[x].payload
}
ready
Using Object.keys()
var sum = 0;
var keys = Object.keys(obj);
for (var x=0; x<keys.length; ++x) {
    sum += obj[keys[x]].payload
}
ready
Using Object.keys(), cached length, assuming object is arraylike
var sum = 0;
var len = Object.keys(obj).length;
for (var x=0; x<len; ++x) {
    sum += obj[x].payload
}
ready
Array Performance known length
var sum = 0;
for (var x=0; x<10000; ++x) {
    sum += arr[x].payload
}
ready
just testing len portion of test 5
var len = Object.keys(obj).length;
ready
Object using jquery $.each
var sum = 0;
$.each(obj, function(key, value) {
   sum += value.payload;
});
ready

Revisions

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