Run results for: Performance of JavaScript .forEach, .map and .reduce vs for and for..of (fork)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

raw iteration: forEach

163/s

raw iteration: for..of

122/s

reduce comparision: for..of

96/s

reduce comparision: .reduce

90/s

map comparison: .map

78/s

map comparison: for..of

43/s

View exact numbers

Test name	Executions per second
✓ raw iteration: forEach	163 Ops/sec
raw iteration: for..of	122 Ops/sec
reduce comparision: for..of	96 Ops/sec
reduce comparision: .reduce	90 Ops/sec
map comparison: .map	78 Ops/sec
map comparison: for..of	43 Ops/sec

Script Preparation code:

function generateTestArray() {
  const result = [];
  for (let i = 0; i < 1000000; ++i) {
    result.push(i);
  }
  return result;
}
window.array = generateTestArray();

Tests:

map comparison: for..of
const r = []; for(const x of array) { r.push(x); }
map comparison: .map
array.map(x => x)
reduce comparision: for..of
let r = 0; for (const x of array) { r += x; }
reduce comparision: .reduce
array.reduce((p, x) => p + x, 0);
raw iteration: for..of
for(const x of array) {}
raw iteration: forEach
array.forEach(x => {})