Run results for: flatMap() vs filter().map() vs reduce() vs forEach()

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser: Chrome 120

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

forEach

1K/s

reduce

752/s

filter().map()

561/s

flatMap()

189/s

View exact numbers

Script Preparation code:

var arr = [];
var i = 0;

while (i <= 1E5) arr[i] = i++;

Tests:

filter().map()
arr.filter(x => x % 3).map(x => x/100)
flatMap()
arr.flatMap(x => x % 3 ? [x/100] : [])
reduce
arr.reduce((result, x) => { if (x % 3) result.push(x / 100); return result; }, [])
forEach
var result = []; arr.forEach(x => { if (x % 3) result.push(x / 100); });