For Loop vs. Optimized For Loop

JavaScript performance comparison

Revision 29 of this test case created

Info

A speed comparison between for loops.

Preparation code

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Preparation code output

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Testing in unknown unknown
Test Ops/sec
Customary For Loop
var anchors = document.getElementsByTagName("a");

for (i = 0; i < anchors.length; i++) {
  anchors[i].style.color = "red";
}
pending…
Optimized For Loop
var anchors = document.getElementsByTagName("a");

for (var i = anchors.length - 1; i >= 0; i -= 1) {
  anchors[i].style.color = "red";
}
pending…
Optimized For Loop2
var anchors = document.getElementsByTagName("a");

for (var i = anchors.length; --i >= 0;) {
  anchors[i].style.color = "red";
}
pending…

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