Run results for: Object.fromEntries vs reduce vs for loop

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.0.0 Safari/537.36

Browser: Chrome 130

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

For loop

8K/s

Object.fromEntries

810/s

Reduce (creating temporary objects)

26/s

View exact numbers

Test name	Executions per second
✓ For loop	7,745 Ops/sec
Object.fromEntries	810 Ops/sec
Reduce (creating temporary objects)	26 Ops/sec

Script Preparation code:

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

Tests:

Object.fromEntries
Object.fromEntries(data.map((key) => [key, 'x']));
Reduce (creating temporary objects)
data.reduce((acc, k) => ({ ...acc, [k]: 'x' }), {});
For loop
const obj = {}; for (const d of data) { obj[d] = 'x'; }