ChildNodes: Array.slice vs Loop

JavaScript performance comparison

Revision 4 of this test case created

Preparation code

<div id="test">
<div>a</div>
<div>b</div>
<div>c</div>
<div>d</div>
<div>e</div>
<div>f</div>
<div>g</div>
</div>
<script>
Benchmark.prototype.setup = function() {
    var childNodes = document.getElementById('test');
};
</script>

Preparation code output

a
b
c
d
e
f
g

Test runner

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Testing in unknown unknown
Test Ops/sec
Array.slice
var ary = Array.prototype.slice(childNodes, 0);
pending…
Loop
var length = childNodes.length;
var ary = [];
for (var i = 0; i < length; i++) {
  ary.push(childNodes[i]);
}
pending…
Loop with Array preps
var length = childNodes.length;
var ary = [];
for (var i = 0; i < length; i++) {
  ary[i] = childNodes[i];
}
pending…
While loop (reverse)
var length = childNodes.length;
var ary = [];
while (length) {
  ary.push(childNodes[--length]);
}
pending…
While loop
var length = childNodes.length;
var ary = [];
while (length) {
  ary.unshift(childNodes[--length]);
}
pending…

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