Performance of for-in loop vs for loop over Object.keys

JavaScript performance comparison

Revision 79 of this test case created by

Preparation code


      
      <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>

Test runner

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
for-in loop
var sum = 0;
for (var x in obj) {
    sum += obj[x].payload;
}
pending…
for loop over 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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