Run results for: Looping through massive array

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.101 Safari/537.36

Browser: Chrome 53

Operating system: Windows

Device Platform: Other

Date tested: 8 years ago

Test name	Executions per second
Basic for loop	121.0 Ops/sec
For loop but caching the length	3571.6 Ops/sec
While loop that imitates a for loop	118.0 Ops/sec
While loop that imitates a for loop caching len	3642.1 Ops/sec
While loop in reverse simplifying the test	1800.5 Ops/sec
While looping by popping values	8760227.0 Ops/sec
for ... in loop	5784469.5 Ops/sec
for ... in loop with integer test	5418856.0 Ops/sec
For loop testing on existence rather than lengt	9429943.0 Ops/sec
For loop testing on existence plus array lookup	9693594.0 Ops/sec
For testing on existence rather than length array	9282144.0 Ops/sec
For reference	10606084.0 Ops/sec
Array.forEach() native implementation.	8541040.0 Ops/sec
For reference against forEach()	9639600.0 Ops/sec

Script Preparation code:

var arr = new Array(99999);

Tests:

Basic for loop
for (var i=0; i<arr.length; i++) {}
For loop but caching the length
for (var i=0, len=arr.length; i<len; i++) {}
While loop that imitates a for loop
var i = 0; while (i<arr.length) { i++; }
While loop that imitates a for loop caching len
var i=0, len=arr.length; while (i<len) { i++; }
While loop in reverse simplifying the test
var i = arr.length; while (i--) {}
While looping by popping values
var x; while (x = arr.pop()) {}
for ... in loop
for (var i in arr) {}
for ... in loop with integer test
var isInt = /(\^[0-9]$)|(\^[1-9][0-9]+$)/; for (var i in arr) { if(!isInt.test(i)){continue;} }
For loop testing on existence rather than lengt
for (var i=0; arr[i]; i++) {}
For loop testing on existence plus array lookup
for (var i=0; arr[i]; i++) { var x = arr[i]; }
For testing on existence rather than length array
for (var i=0, x; x = arr[i++];) {}
For reference
for (var i=0, len=arr.length; i<len; i++) { var x = arr[i]; }
Array.forEach() native implementation.
arr.forEach(function(x){});
For reference against forEach()
var f=function(x){}; for (var i=0, len=arr.length; i<len; i++) { f(arr[i]); }