Run results for: flatMap + reduce vs reduce + reduce

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Firefox/91.0 Waterfox/91.4.0

Browser: Firefox 91

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
flatMap + reduce	2.3 Ops/sec
reduce + reduce	5.4 Ops/sec

Script Preparation code:

var arr = Array(10_000).fill([...Array(1000)].map(e=>~~(Math.random()*50)))

Tests:

flatMap + reduce
arr.flatMap(inner => inner).reduce((a, b) => Math.max(a, b))
reduce + reduce
arr.reduce((total, inner) => total + inner.reduce((a, b) => Math.max(a, b)))