Is it worth caching the length of an array in a Javascript loop? (v151)

Revision 151 of this benchmark created by PV on

Description

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

Preparation HTML

<script>
var n = 100;
var myArray = new Array( n );
for( var i = 0; i < n; i ++ )
{
  myArray[i] = i+1;
}
</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--) {
 
}
ready
for check index
for (var i = 0; myArray[i++];) {

}
ready
for in array
for (var i in myArray){

}
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.