Run results for: flatMap vs reduce

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.106 YaBrowser/21.6.0.1108 Yowser/2.5 Safari/537.36

Browser: Yandex Browser 21

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
reduce with concat	9.4 Ops/sec
flatMap	282.8 Ops/sec

Script Preparation code:

var arr = Array(10_000).fill(0)

Tests:

reduce with concat
arr.reduce((acc, x) => [...acc, x, x], [])
flatMap
arr.flatMap(x => [x, x])

Run results for: flatMap vs reduce

reduce with concat

flatMap