Run results for: FlatMap method vs for loop

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/129.0.0.0 Safari/537.36

Browser: Chrome 129

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

flatMap

4K/s

for loop

3K/s

View exact numbers

Test name	Executions per second
✓ flatMap	3,645 Ops/sec
for loop	2,825 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; }