for vs forEach

JavaScript performance comparison

Revision 449 of this test case created by

Preparation code 

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

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Testing in CCBot 2.0.0 / Other 0.0.0
Test Ops/sec
forEach 
values.forEach(add);
 pending…
for loop, simple 
for (i = 0; i < values.length; i++) {
  add(values[i]);
}
 pending…
for loop, cached length 
var len = values.length;
for (i = 0; i < len; i++) {
  add(values[i]);
}
 pending…
for loop, reverse 
for (i = values.length - 1; i >= 0; i--) {
  add(values[i]);
}
 pending…
forEach more local 
(function() {
  var sum = 0;
  values.forEach(function(val) {
    sum += val;
  });
})();
 pending…
while 
var len = values.length;
i = 0;
while (i < len) {
  add(values[i++]);
}
 pending…

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Revisions

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