Run results for: flatMap vs reduce

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 14_7 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/95.0.4638.50 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 95

Operating system: iOS 14.7

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
reduce with concat	3.8 Ops/sec
flatMap	7424.9 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