for vs forEach

JavaScript performance comparison

Revision 169 of this test case created

Info

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

Preparation code

<script>
  var i, values = [],
      sum = 0;
  for (i = 0; i < 10000; i++) {
   values[i] = i;
  }
 
  function add(val) {
   sum += val;
  }
</script>
<script src="//cdnjs.cloudflare.com/ajax/libs/lodash.js/2.4.1/lodash.backbone.js"></script>

Preparation code output

Test runner

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

Java applet disabled.

Testing in unknown unknown
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
for (var len = values.length, 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…
lodash each
var sum = 0;
_.each(values, function(v) {
  sum += v;
});
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. Here’s a list of current revisions for this page:

0 comments

Add a comment