Run results for: flatMap() vs filter().map() vs reduce() v8

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_2 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.2 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.2

Device Platform: Mobile

Date tested: one year ago

reduce()

39K/s

filter().map()

26K/s

flatMap()

15K/s

View exact numbers

Script Preparation code:

var arr = [];
var i = 0;

while (i <= 10000) arr[i] = i++;

Tests:

filter().map()
arr.filter(x => x % 2).map(x => x/100)
flatMap()
arr.flatMap(x => x % 2 ? x/100 : [])
reduce()
arr.reduce((newArray, x) => { if (x % 2) { newArray.push(x / 100) } return newArray }, [])