for vs forEach

JavaScript performance comparison

Revision 237 of this test case created by muffin

Preparation code

<script>
  var i, values = [],
      sum = 0;
  for (i = 0; i < 1000; i++) {
   values[i] = i;
  }
  
  function add(val) {
   sum += val;
   return true;
  }
</script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2/jquery.min.js"></script>

    

Preparation code output

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2/jquery.min.js"></script>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

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…
Native JS prep func
values.every(add);
pending…
Native JS annon func
values.every(function(val) {
  sum += val;
  return true;
});
pending…
Reverse while Loop
i = values.length
while (i--) {
  add(values[i]);
}
pending…
JQuery
values.each(add);
pending…
For in
for (value in values) {
  add(value);
}
pending…

Compare results of other browsers

Revisions

You can edit these tests or add even more tests to this page by appending /edit to the URL.

0 Comments