Fastest array loops in Javascript (v410)

Revision 410 of this benchmark created by Denis on

Preparation HTML

<script>
  // Populate the base array
  var arr = [];
  for (var i = 0; i < 1000; i++) {
    arr[i] = i;
  }
var len= arr.length;
  function someFn(ix) {
    return Math.random();
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
While length--
var l = arr.length;
while(l--) {
  someFn(arr[l]);
}
ready
While loop, basic
var i = -1;
while (++i < arr.length) {
  someFn(arr[i]);
}
ready
For loop, cached
for (var i = 0, len = arr.length; i < len; i++) {
  someFn(arr[i]);
}
ready
For loop, basic
for (var i = 0; i < arr.length; i++) {
  someFn(arr[i]);
}
ready
For loop, adv
var i = 0
for (; i < len; ++i) {
  someFn(arr[i]);
}
ready
just for
for (var i = 0; i < len; i++) {
  someFn(arr[i]);
}
ready
Cla
for (var i = 0, l = arr.length; i !== l; i++) {
  someFn(arr[i]);
}
ready
condition
var i = len;

for (i; --i;) {
    someFn(arr[i]);
}
ready

Revisions

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