Underscore.each vs jQuery.each vs. for loop

JavaScript performance comparison

Revision 13 of this test case created by Morgan Roderick

Preparation code

<script src="//ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>

<script src="//documentcloud.github.com/underscore/underscore-min.js"></script>

<script>
  var pi = Math.PI
  var a = new Array(10000),
      e;
</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
jQuery.each
 
$.each(a, function() {
 e = pi;
});
 pending…
good old for loop
 
for (var i = 0, len = a.length; i < len; i++) {
 e = pi;
};
 pending…
underscore.each
 
_.each(a, function(item) {
 e = pi;
});
 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:

1 comment

Bruno Windels commented : ∞

Why is the array value not read inside all loops? It seems to me that this gives an advantage to the variations of the good old for loop, since other implementations (jQuery, Underscore, iterator) always read the source array, whether the value is used inside the loop or not.

Add a comment