Underscore.each vs jQuery.each vs. for loop

JavaScript performance comparison

Revision 16 of this test case created

Info

Adding an optimized for loop.

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;
  
  // cf https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/array/foreach
  if (!Array.prototype.mozForEach) {
   Array.prototype.mozForEach = function(fun /*, thisp */ ) {
    "use strict";
  
    if (this === void 0 || this === null) throw new TypeError();
  
    var t = Object(this);
    var len = t.length >>> 0;
    if (typeof fun !== "function") throw new TypeError();
  
    var thisp = arguments[1];
    for (var i = 0; i < len; i++) {
     if (i in t) fun.call(thisp, t[i], i, t);
    }
   };
  }
</script>

Preparation code output

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Testing in unknown unknown
Test Ops/sec
jQuery.each
 
$.each(a, function() {
 e = pi;
});
 pending…
good old for loop
 
var length = a.length;
for (var i = 0, len = length; i < len; i++) {
 e = pi;
};
 pending…
underscore.each
 
_.each(a, function(item) {
 e = pi;
});
 pending…
mozilla foreach
 
a.mozForEach(function() {
 e = pi;
});
 pending…
Another good old optimized 'for loop'
 
for (var i = a.length; i--;) {
 e = pi;
};
 pending…

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Revisions

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