Run results for: FlatMap method vs for loop

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4.1 Safari/605.1.15

Browser: Safari 17

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

flatMap

10K/s

for loop

3K/s

View exact numbers

Test name	Executions per second
✓ flatMap	10,439 Ops/sec
for loop	3,474 Ops/sec

Script Preparation code:

var arr = Array(10_000).fill(0);

Tests:

flatMap
arr.flatMap(x => [x, x * 2]);
for loop
const n = arr.length; const acc = new Array(n * 2); for (let i = 0; i < n; i++){ const x = arr[i]; acc[i * 2] = x; acc[i * 2 + 1] = x * 2; }