Run results for: forEach vs reduce vs map vs filter vs for (w/o reading .length)

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; CLT-L09) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.98 Mobile Safari/537.36

Browser: Chrome Mobile 97

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
forEach	66.5 Ops/sec
reduce	66.4 Ops/sec
map	63.3 Ops/sec
filter	65.3 Ops/sec
for	70.5 Ops/sec

Script Preparation code:

var arr = [];
for (var i = 0; i < 12345; i++) {
  arr[i] = i;
}

function someFn(i) {
  return (i * 3 * 8 / 1200 * 0.002 / 40 * 0.2);
}

var sumForEach = 0,
  sumReduce = 0,
  sumMap = 0,
  sumFilter = 0,
  sumFor = 0;

Tests:

forEach
arr.forEach(item => sumForEach += someFn(item));
reduce
sumReduce = arr.reduce((lastValue, item) => { return sumReduce += someFn(item); });
map
arr.map(item => (sumMap += someFn(item)));
filter
arr.filter(item => (sumFilter += someFn(item)));
for
for (var j = arr.length; j > 0; --j) { sumFor += arr[j]; }

Run results for: forEach vs reduce vs map vs filter vs for (w/o reading .length)

Use for without read xx.length at each iteration

forEach

reduce

map

filter

for