Run results for: Benchmark: flatMap vs reduce vs while

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 14_5_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Mobile/15E148 [FBAN/FBIOS;FBDV/iPhone13,2;FBMD/iPhone;FBSN/iOS;FBSV/14.5.1;FBSS/3;FBID/phone;FBLC/en_US;FBOP/5]

Browser: Mobile Safari 14

Operating system: iOS 14.5.1

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
flatMap	27058.3 Ops/sec
reduce	172.8 Ops/sec
while	12181.0 Ops/sec

Script Preparation code:

var n = 1000

Tests:

flatMap
[...Array(n)].flatMap((x,i) => [++i,i++])
reduce
[...Array(n).keys()].reduce((acc, cur) => [...acc, ++cur, cur++], [])
while
let res = [], i=0; while(n>i++) res.push(i, i);