Performance of Array vs. Object

JavaScript performance comparison

Revision 11 of this test case created

Info

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

Preparation code

 
<script>
  Benchmark.prototype.setup = function() {
    var arr = [],
        i,
        obj = {};
    for(i = 10000; i < 50000; i += 1) {
        var o = {payload:i};
        arr.push(o);
        obj[i] = o;
    }
    
  };
</script>

Test runner

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Testing in unknown unknown
Test Ops/sec
Array Performance
 
var sum = 0;
for (var x=10000; x<50000; ++x) {
    sum += arr[x].payload
}
 pending…
Object Performance
 
var sum = 0;
for (var x in obj) {
    sum += obj[x].payload;
}
 pending…
Object Performance using known length
 
var sum = 0;
for (var x=0; x<10000; ++x) {
    sum += obj[x].payload
}
 pending…
Using Object.keys()
 
var sum = 0;
var keys = Object.keys(obj);
for (var x=0; x<keys.length; ++x) {
    sum += obj[keys[x]].payload
}
 pending…

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Revisions

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