for vs for..in vs forEach

JavaScript performance comparison

Revision 617 of this test case created by Evgenii

Preparation code

<script>
'use strict';
  var i, values = [],
      sum = 0;
  for (i = 0; i < 10000; i++) {
   values[i] = i;
  }
  
  function add(val) {
   sum += val;
  }

  function forEachFN(array,fn){
    var l = array.length;
    while(l--){fn(array[l])}
  }
  
  var values2 = JSON.parse(JSON.stringify(values));
  values2.forEach = function(fn){
    var l = this.length;
    while(l--){fn(this[l]);}
  }

</script>
    

Test runner

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Java applet disabled.

Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
local
(function() {
 var sum = 0;
 values.forEach(function (val) {
   sum += val;
 });
})();
pending…

Revisions

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