Fastest array loops in Javascript (v303)

Revision 303 of this benchmark created by Glen on

Preparation HTML

<script>
  // Populate the base array
  var arr = [];
  for (var i = 0; i < 1000; i++) {
    arr[i] = i;
  }

  function someFn(ix) {
    return ix * 5 + 1 / 3 * 8;
  }
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
For loop, basic
for (var i = 0; i < arr.length; i++) {
  someFn(arr[i]);
}
ready
For length--
for(var l = arr.length; l--;) {
  someFn(arr[l]);
}
ready
While length--
var l = arr.length;
while(l--) {
  someFn(arr[l]);
}
ready
Without braces
for(var i = arr.length; --i >= 0; someFn(arr[i]));
ready
For length !== 0
for(var l = arr.length; l-- !== 0;) {
  someFn(arr[l]);
}
ready

Revisions

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