Benchmark: flatMap vs reduce vs loop filtering performance vs flat.map

Script Preparation code:

var arr = Array.from({length:10000}, (v, i) => ({name: i, assigned: Math.random() < 0.5}));

Tests:

flatMap
arr.flatMap((o) => (o.assigned ? [o.name] : []));
reduce with push
arr.reduce((a, o) => (o.assigned && a.push(o.name), a), [])
loop with push
{ const a = []; for (const o of arr) if (o.assigned) a.push(o.name); }
map flat()
arr.flat().map((o) => o.assigned ? [o.name] : [])

Rendered benchmark preparation results:

Previous results

Latest run results:

Run details: (Test run date: 5 months ago)

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36

Browser/OS: Chrome 142 on Linux

Related benchmarks:

flatMap vs reduce vs loop filtering performance vs flat.map (version: 1)