Performance of Array vs. Object

JavaScript performance comparison

Revision 182 of this test case created by

Preparation code


      
      <script>
Benchmark.prototype.setup = function() {
  function makeRandomID() {
    var text = "";
    var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
  
    for (var i = 0; i < 5; i++)
      text += possible.charAt(Math.floor(Math.random() * possible.length));
  
    return text;
  }
  
  
  var arr = [],
    i,
    obj = {},
    randomKeys = [],
    randomObj = {},
    key;
  for (i = 0; i < 10000; i += 1) {
    var o = {
      payload: i
    };
    arr.push(o);
    obj[i] = o;
    key = makeRandomID();
    randomKeys[i] = key;
    randomObj[key] = o;
  }

};
</script>

Test runner

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
Using randomObj
var sum = 0;
for (var x = 0; x < randomKeys.length; ++x) {
  sum += randomObj[randomKeys[x]].payload
}
pending…
Array Performance
var sum = 0;
for (var x = 0; x < arr.length; ++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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