Run results for: Benchmark: flatMap vs reduce vs while

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; Mi 9 Lite Build/QKQ1.190828.002; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/88.0.4324.152 Mobile Safari/537.36 [FB_IAB/FB4A;FBAV/305.1.0.40.120;]

Browser: Chrome Mobile 88

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
flatMap	1309.9 Ops/sec
reduce	202.8 Ops/sec
while	4807.9 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);