Performance of Array vs. Object

JavaScript performance comparison

Revision 45 of this test case created

Info

Added tests using Underscore.js and jQuery.js

Preparation code

<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.5.2/underscore-min.js"></script><script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
 
<script>
Benchmark.prototype.setup = function() {
    var arr = [],
      i,
      obj = {};
    for (i = 0; i < 10000; i += 1) {
      var o = {
        payload: i
      };
      arr.push(o);
      obj[i] = o;
    }
};
</script>

Preparation code output

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Testing in unknown unknown
Test Ops/sec
Array Performance
var sum = 0;
for (var x = 0, len = arr.length; x < len; ++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, len = keys.length; x < len; ++x) {
  sum += obj[keys[x]].payload
}
pending…
Array in
var sum = 0;
for (var x in arr) {
  sum += x.payload
}
pending…
Array using Underscore.js
var sum = 0;
_.each(arr, function(x) {
  sum += x.payload
});
pending…
Object using Underscore.js
var sum = 0;
_.each(obj, function(x) {
  sum += x.payload
});
pending…
Array with index using jQuery.js
var sum = 0;
$.each(arr, function(x) {
  sum += arr[x];
});
pending…
Object with index using jQuery.js
var sum = 0;
$.each(obj, function(x) {
  sum += obj[x].payload;
});
pending…

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