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

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36

Browser: Chrome 125

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Benchmark engine: Benchmark.js

Reduce (reuse object)

2K/s

forEach

2K/s

Map

2K/s

Object.assign

271/s

Object.fromEntries

218/s

Reduce (creating temporary objects)

68/s

View exact numbers

Test name	Executions per second
✓ Reduce (reuse object)	2,458 Ops/sec
forEach	1,749 Ops/sec
Map	1,511 Ops/sec
Object.assign	271 Ops/sec
Object.fromEntries	218 Ops/sec
Reduce (creating temporary objects)	68 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 })) );