Native Array map vs. emulated (v2)

Revision 2 of this benchmark created by Ryan Grove on October 12, 2010

Preparation HTML

<script src="http://fuji.jetpants.com/yui/devcombo/yui3-dev?build/yui/yui-min.js&build/loader/loader-min.js"></script>
<script>
  var Y = YUI({
   comboBase: 'http://fuji.jetpants.com/yui/combo/yui3-dev?',
   combine: true,
   root: 'build/'
  }).use('array-extras'),
      states = ["Alabama", "Alaska", "Arizona", "Arkansas", "California", "Colorado", "Connecticut", "Delaware", "Florida", "Georgia", "Hawaii", "Idaho", "Illinois", "Indiana", "Iowa", "Kansas", "Kentucky", "Louisiana", "Maine", "Maryland", "Massachusetts", "Michigan", "Minnesota", "Mississippi", "Missouri", "Montana", "Nebraska", "Nevada", "New Hampshire", "New Jersey", "New Mexico", "New York", "North Dakota", "North Carolina", "Ohio", "Oklahoma", "Oregon", "Pennsylvania", "Rhode Island", "South Carolina", "South Dakota", "Tennessee", "Texas", "Utah", "Vermont", "Virginia", "Washington", "West Virginia", "Wisconsin", "Wyoming"],
      results;
  
  // YUI3-style emulated each().
  
  function each(a, f, o) {
   var l = (a && a.length) || 0,
       i;
   for (i = 0; i < l; i = i + 1) {
    f.call(o || this, a[i], i, a);
   }
  }
  
  function map(array, callback, thisObject) {
   var i = 0,
       len = array.length,
       results = [];
  
   for (; i < len; ++i) {
    results.push(callback.call(thisObject, array[i], i, array));
   }
  
   return results;
  }
  
  function map_dupe(array, callback, thisObject) {
   var i = 0,
       len = array.length,
       results = array.concat();
  
   for (; i < len; ++i) {
    results[i] = callback.call(thisObject, array[i], i, array);
   }
  
   return results;
  }
  
  // YUI3-style emulated map().
  
  function map_each(array, callback, thisObject) {
   var results = [];
   each(array, function(item, i, a) {
    results.push(callback.call(thisObject, item, i, a));
   });
   return results;
  }
  
  function callback(item) {
   return item + 'pants';
  }
</script>

Test runner

results = states.map(callback);

results = map(states, callback);

results = map_dupe(states, callback);

results = map_each(states, callback);

results = Y.Array.map(states, callback);

Revisions

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

• Revision 1: published by Ryan Grove on October 12, 2010
• Revision 2: published by Ryan Grove on October 12, 2010