underscore shuffle (v3)

Revision 3 of this benchmark created on

Preparation HTML

<style>
.debug-block {
  border: 1px solid black;
  margin-bottom: 15px;
}
.debug-block span:first-child {
  font-weight: bold;
  display: block;
}
.failed {background: salmon;}
.passed {background: lightblue;}
</style>
<script src='http://code.jquery.com/jquery.js'></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/underscore.js/1.5.2/underscore.js">
</script>
<script>var underscore = _.noConflict();</script>
<script src="//rawgithub.com/lodash/lodash/master/dist/lodash.js"></script>
<script>var lodash = _.noConflict();</script>
<script>
var sortbyrandom = function(arr){
  arr = arr.slice();
  return arr.sort(function() { return 0.5 - Math.random(); });
}

var knut3 = function(arr) {
  arr = arr.slice();
  for (var l = arr.length; l > 1;) {
    var i = Math.floor(Math.random() * l--);
    var t = arr[l];
    arr[l] = arr[i];
    arr[i] = t;
  }
  return arr;
}
</script>

<i>Example output from methods. (lightblue - passed; salmon - failed)</i>
<div id="debug"></div>

<script>
var $debug = $('#debug');
var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 'foo', 'bar', true, false];

function test(arr, func) {
  arr = arr.slice();
  var res = func(arr), testOk = true;
  if (!lodash.isEmpty(lodash.difference(arr, res))) {
    console.log('diff', lodash.difference(arr, res));
    testOk = false; 
  }
  if (arr.join(',') == res.join(',')) {
    console.log('not shuffled', arr.join(','), res.join(','));
    testOk = false;
  }
  if (arr.sort().join(',') != res.sort().join(',')) {
    console.log('not same', arr.sort().join(','), res.sort().join(','));
    testOk = false;
  }
  return testOk;
}

function debugWrite(testname, arr, func) {
  var $div = $('<div></div>', {class:'debug-block'});
  $div.addClass(test(arr, func) ? 'passed' : 'failed');
  var html = '<span>'+testname+'</span>';
  html += '<span>'+JSON.stringify(func(arr))+'</span>';
  $div.html(html);
  $debug.append($div);
}

/******************************************/
debugWrite('underscore_shuffle', arr, function (o) { return underscore.shuffle(o); });
debugWrite('lodash_shuffle', arr, function (o) { return lodash.shuffle(o); });
debugWrite('sortbyrandom', arr, function (o) { return sortbyrandom(o); });
debugWrite('knut3', arr, function (o) { return knut3(o); });
/******************************************/

var arr = Array(100);
for (var i = 0; i < 100; i++) {
  arr[i] = i;
}
</script>

Setup

var lodash = window.lodash,
        knut3 = window.knut3,
        sortbyrandom = window.sortbyrandom,
        underscore = window.underscore;

Test runner

Ready to run.

Testing in
TestOps/sec
Underscrore.shuffle
underscore.shuffle(arr);
ready
native sort by random
sortbyrandom(arr);
ready
Knuth-Fisher-Yates
knut3(arr);
ready
lodash.shuffle
lodash.shuffle(arr);
ready

Revisions

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