Run results for: Object.fromEntries vs reduce vs Map vs Object.assign vs forEach

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0

Browser: Chrome 120

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

Reduce (reuse object)

3K/s

Map

2K/s

forEach

2K/s

Object.fromEntries

275/s

Object.assign

250/s

Reduce (creating temporary objects)

101/s

View exact numbers

Test name	Executions per second
✓ Reduce (reuse object)	3,344 Ops/sec
Map	1,977 Ops/sec
forEach	1,960 Ops/sec
Object.fromEntries	275 Ops/sec
Object.assign	250 Ops/sec
Reduce (creating temporary objects)	101 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());
forEach
const result = {}; Object.keys(data).forEach((key) => { result[key] = data[key].toString(); });
Object.assign
Object.assign( {}, ...Object.entries(data).map(([key, value]) => ({ [key]: value })) );