Benchmark: flat vs flatMap vs reduce vs reduce push vs forEach push vs concat spread

Script Preparation code:

var arr = Array(100).fill(Array(20).fill(Math.random()*50))

Tests:

reduce
arr.reduce((acc, val) => acc.concat(val), [])
flatMap
arr.flatMap(x => x)
flat
arr.flat()
reduce push
arr.reduce((acc, val) => { if (val) val.forEach(a => acc.push(a)); return acc; }, [])
forEach push
let acc = []; arr.forEach(val => { val && val.forEach(v => acc.push(v)); }), acc;
concat spread
[].concat(...arr)

Rendered benchmark preparation results:

Previous results

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Latest run results:

Run details: (Test run date: one month ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36

Browser/OS: Chrome 126 on Windows

flat vs flatMap vs reduce vs reduce push vs forEach push vs concat spread (version: 0)