for vs forEach (v77)

Revision 77 of this benchmark created on

Description

Is it faster to use the native forEach or just loop with for?

Preparation HTML

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

function forEach(arr, fn) {
  var i, l, el;
  for (i = 0, l = arr.length; i < l; i++) {
    el = arr[i]
    if (el !== undefined) {
      fn(el, i, arr, this);
    }
  }
}
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
forEach
values.forEach(add);
ready
for loop, simple
for (i = 0; i < values.length; i++) {
 add(values[i]);
}
ready
for loop, cached length
var len = values.length;
for (i = 0; i < len; i++) {
 add(values[i]);
}
ready
for loop, reverse
for (i = values.length - 1; i >= 0; i--) {
 add(values[i]);
}
ready
forEach more local
(function() {
 var sum = 0;
 values.forEach(function(val) {
  sum += val;
 });
})();
ready
custom forEach
forEach(values, add);
ready

Revisions

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