Info

This is meant to test which way is the fastest to transverse an array, specially when performance is important

Preparation code

 
<script>
  Benchmark.prototype.setup = function() {
    var thingy = [1, "test", 44, true, false, "tester", 212313213, "testestetestetest stest ,...!", 2, true, "more", "extra", "stuff", "to", "make", "it", "more", "challenging"];
    var thingy2;
    
    var testArray = [];
    for (i = 0; i < 100000; i++) {
      testArray.push(i);
    }
  };
</script>

Test runner

Warning! For accurate results, please disable Firebug before running the tests. (Why?)

Java applet disabled.

for (var i in thingy) {
  thingy2 = i;
}

for (var i = 0; i < thingy.length; i++) {
  thingy2 = thingy[i];
}

var length = thingy.length;
for (var i = 0; i < length; i++) {
  thingy2 = thingy[i];
}

for (var i = 0, length = thingy.length; i < length; i++) {
  thingy2 = thingy[i];
}

for (var i = thingy.length - 1; i >= 0; i--) {
  thingy2 = thingy[i];
}

for (var i = thingy.length; i--;) {
  thingy2 = thingy[i];
}

for (i = 0; i < testArray.length; i++) {
  var a = testArray[i];
}

var testArrayLength = testArray.length;
for (i = 0; i < testArrayLength; i++) {
  var a = testArray[i];
}

for (i in testArray) {
  var a = testArray[i];
}

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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:

• Revision 1: published by Vaughn on 16th February 2013
• Revision 2: published on 16th February 2013
• Revision 3: published on 16th February 2013
• Revision 4: published on 16th February 2013
• Revision 5: published on 16th February 2013

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