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/605.1.15 (KHTML, like Gecko) Version/18.6 Safari/605.1.15

Browser: Safari 18

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 9 months ago

raw iteration: forEach

2K/s

raw iteration: for..of

1K/s

reduce comparision: .reduce

1K/s

reduce comparision: for..of

1K/s

map comparison: .map

696/s

map comparison: for..of

532/s

View exact numbers

Test name	Executions per second
✓ raw iteration: forEach	1,830 Ops/sec
raw iteration: for..of	1,434 Ops/sec
reduce comparision: .reduce	1,225 Ops/sec
reduce comparision: for..of	1,167 Ops/sec
map comparison: .map	696 Ops/sec
map comparison: for..of	532 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 => {})