Run results for: Array loop vs for loop vs for loop cached

Run details:

User agent: Mozilla/5.0 (Android 13; Mobile; rv:122.0) Gecko/122.0 Firefox/122.0

Browser: Firefox Mobile 122

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

for each cached reversed

93K/s

for each

79K/s

for each cached

78K/s

foreach

54K/s

map

27K/s

View exact numbers

Test name	Executions per second
✓ for each cached reversed	92,936 Ops/sec
for each	79,064 Ops/sec
for each cached	77,794 Ops/sec
foreach	54,209 Ops/sec
map	26,686 Ops/sec

Script Preparation code:

function getArr() {
  	return Array(1000).fill(1);
//	var arr = [];
//    for (var i = 0; i < 1000; i++) {
//      arr[i] = i;
//    }
//    return arr;
}
  
function someFn(i) {
  return i * 3 * 8;
}

Tests:

foreach
var arr = getArr(); arr.forEach((item) => { someFn(item); })
map
var arr = getArr(); arr.map(item => someFn(item));
for each
var arr = getArr(); for (var i = 0; i < arr.length; i++) { someFn(arr[i]); }
for each cached
var arr = getArr(); for (var i = 0, len = arr.length; i < len; i++) { someFn(arr[i]); }
for each cached reversed
var arr = getArr(); for (var i = arr.length - 1; i >= 0; i--) { someFn(arr[i]); }