Is it worth caching the length of an array in a Javascript loop? (v162)

Revision 162 of this benchmark created by sohei_katana on

Description

http://stackoverflow.com/questions/5349425/whats-the-best-to-loop-an-array-in-javascript

Preparation HTML

<script>
  
 var myArray = [];
        var i = 0;
        while (i < 10000000) {
            myArray[i] = 'item' + i;
            i++
        }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
With caching
for (var i = 0, len = myArray.length; i < len; i++) {

}
ready
Without caching
for (var i = 0; i < myArray.length; i++) {

}
ready
Counting down
for (var i = myArray.length; i--;) {

}
ready
caching length outside for loop
len = myArray.length;

for (var i = 0; i < len; i++) {

}
ready
while loop
len = myArray.length;
while (len--) {
 // blah blah
}
ready
for check index
for (var i = 0; myArray[i++];) {

}
ready

Revisions

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