NodeList To Array

JavaScript performance comparison

Revision 42 of this test case created by Alinaki

Info

http://stackoverflow.com/questions/3199588/fastest-way-to-convert-javascript-nodelist-to-array

Preparation code

<div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div><div></div>
<script>
Benchmark.prototype.setup = function() {
    var nodeList = document.querySelectorAll('div');
    var Slice = function( arr ){ return Array.prototype.slice.call( arr ) };
    var Arrayify = function ( nodeList ) {
    var outputArr = [], i = nodeList.length;
    while(i--){outputArr[i]=nodeList[i]};
    return outputArr;
    }
    var ArrayForEach = function( nodeList ) {
    var outputArr = [];
    Array.prototype.forEach.call( nodeList, function(node){outputArr.push(node)} );
    return outputArr;
    }
};
</script>

Preparation code output

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Testing in unknown unknown
Test Ops/sec
Array.prototype.slice.call
var arr = Array.prototype.slice.call(nodeList);
pending…
push
var arr = [];
for (var i = 0, n; n = nodeList[i]; ++i) arr.push(n);
pending…
single for
var l = []; // Will hold the array of Node's
for (var i = 0, ll = nodeList.length; i != ll; l.push(nodeList[i++]));
pending…
count back
var arr = [];
for (var i = nodeList.length; i--; arr.unshift(nodeList[i]));
pending…
set length first
var arr = [];
for (var i = 0, ref = arr.length = nodeList.length>>0; i < ref; i++) {
  arr[i] = nodeList[i];
}
pending…
set length first with Array constructor
var ref = nodeList.length,
    arr = new Array(ref);
for (var i = 0; i < ref; i++) {
  arr[i] = nodeList[i];
}
pending…
Set Length First, Terse
var a=[], l=nodeList.length>>0;
for( ; l--; a[l]=nodeList[l] );
pending…
Terse While
var a=[], l=nodeList.length>>0;
while(l--){a[l]=nodeList[l]};
pending…
Cached Array Prototype
var a = Slice( nodeList );
pending…
While as Function
var a = Arrayify( nodeList );
pending…
var arr = ArrayForEach( nodeList );
pending…
Terse While new Array
var l=nodeList.length, a = new Array(l);
while(l--){a[l]=nodeList[l]};
pending…
[].slice.call
var arr = [].slice.call(nodeList);
pending…

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