Run results for: Object.fromEntries vs reduce

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_1_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/131.0.6778.154 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 131

Operating system: iOS 18.1.1

Device Platform: Mobile

Date tested: 4 months ago

Test name	Executions per second
Object.fromEntries	387.2 Ops/sec
Reduce (reuse object)	643.3 Ops/sec
Reduce (creating temporary objects)	0.2 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() }), {});

Run results for: Object.fromEntries vs reduce

Object.fromEntries

Reduce (reuse object)

Reduce (creating temporary objects)