Run results for: for-vs-foreach-vs-forof - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/62.0.3202.94 Safari/537.36

Browser: Chrome 62

Operating system: Windows

Device Platform: Other

Date tested: 6 years ago

Test name	Executions per second
forEach	7611.9 Ops/sec
for	3878.0 Ops/sec
for of	1307.1 Ops/sec
arrowForEach	7503.6 Ops/sec
forBackward	3736.1 Ops/sec
reverse while	3948.8 Ops/sec

Website performance monitoring

Script Preparation code:

var arr = [];
for (var i = 0; i < 1000; i++) {
  arr[i] = i;
}
function someFn(i) {
  return i * 3 * 8;
}

Tests:

forEach
arr.forEach(function (item){ someFn(item); });
for
for (var i = 0, len = arr.length; i < len; i++) { someFn(arr[i]); }
for of
for(xxx of arr){ someFn(xxx); }
arrowForEach
arr.forEach((item)=>{ someFn(item); });
forBackward
for (var i=arr.length-1; i>=0; i--) { someFn(arr[i]); }
reverse while
var i = arr.length; while (i--) { someFn(arr[i]); }