Run results for: Object.fromEntries vs reduce vs Map vs for of

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36

Browser: Chrome 124

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

for of

2K/s

for of without caching entries

2K/s

Reduce (reuse object)

1K/s

Map

936/s

Object.fromEntries

182/s

Reduce (creating temporary objects)

51/s

View exact numbers

Test name	Executions per second
✓ for of	1,745 Ops/sec
for of without caching entries	1,710 Ops/sec
Reduce (reuse object)	1,439 Ops/sec
Map	936 Ops/sec
Object.fromEntries	182 Ops/sec
Reduce (creating temporary objects)	51 Ops/sec

Script Preparation code:

var data = { ...Array.from(Array(10000).keys()) };

Tests:

Object.fromEntries
Object.fromEntries(Object.entries(data).map((key, value) => [key, value]));
Reduce (reuse object)
Object.entries(data).reduce((acc, [k, v]) => { acc[k] = v.toString(); return acc; }, {});
Reduce (creating temporary objects)
Object.entries(data).reduce((acc, [k, v]) => ({ ...acc, [k]: v.toString() }), {});
Map
Object.entries(data).reduce((acc, [k, v]) => { acc.set(k, v.toString()) return acc; }, new Map());
for of
const acc = {} const entries = Object.entries(data); for (let [k, v] of entries) { acc[k] = v; }
for of without caching entries
const acc = {}; for (let [k, v] of Object.entries(data)) { acc[k] = v; }