Run results for: Already sorted versus random

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36

Browser: Chrome 53

Operating system: Mac OS X 10.10.5

Device Platform: Other

Date tested: 8 years ago

Test name	Executions per second
Sort the sorted	2988.1 Ops/sec
Sort the shuffled	3005.0 Ops/sec

Script Preparation code:

function shuffle(array) {
  var currentIndex = array.length, temporaryValue, randomIndex;

  // While there remain elements to shuffle...
  while (0 !== currentIndex) {

    // Pick a remaining element...
    randomIndex = Math.floor(Math.random() * currentIndex);
    currentIndex -= 1;

    // And swap it with the current element.
    temporaryValue = array[currentIndex];
    array[currentIndex] = array[randomIndex];
    array[randomIndex] = temporaryValue;
  }

  return array;
}

var sorted = [];
var shuffled = [];
for (var i = 0; i < 1000; i++) {
  sorted.push('a' + i);
  shuffled.push('a' + i);
}

shuffled = shuffle(shuffled);

Tests:

Sort the sorted
var s2 = sorted.sort();
Sort the shuffled
var s2 = shuffled.sort();

Run results for: Already sorted versus random

Check how much an array sort is faster on an already sorted array or on a randomized one

Sort the sorted

Sort the shuffled