Run results for: forEach vs map + filter

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 16_1_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 16

Operating system: iOS 16.1.1

Device Platform: Mobile

Date tested: 2 years ago

Benchmark engine: Benchmark.js

forEach

14K/s

map + filter

7K/s

View exact numbers

Test name	Executions per second
✓ forEach	14,242 Ops/sec
map + filter	6,742 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
const myItems = [] arr.forEach(item => { if (item > 2) { myItems.push(item) } });
map + filter
const myItems = arr.map(item => (item > 2 ? item : undefined)).filter(Boolean)