Run results for: Object.fromEntries(Array.map) vs Array.reduce (with different methods)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/128.0.0.0 Safari/537.36

Browser: Chrome 128

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Array.reduce (reuse same object)

18K/s

Object.fromEntries(array.map)

2K/s

Array.reduce (use Object.assign)

245/s

Array.reduce (use destructuring)

116/s

View exact numbers

Test name	Executions per second
✓ Array.reduce (reuse same object)	17,716 Ops/sec
Object.fromEntries(array.map)	2,416 Ops/sec
Array.reduce (use Object.assign)	245 Ops/sec
Array.reduce (use destructuring)	116 Ops/sec

Script Preparation code:

var array = Array.from(Array(10000).keys()).map((i) => ({
    id: i,
    count: i * 100,
}))

Tests:

Object.fromEntries(array.map)
Object.fromEntries(array.map(({ id, count }) => [id, count]));
Array.reduce (reuse same object)
array.reduce((obj, { id, count }) => { obj[id] = count; return obj; }, {});
Array.reduce (use Object.assign)
array.reduce((obj, { id, count }) => Object.assign(obj, { [id]: count }), {});
Array.reduce (use destructuring)
array.reduce((obj, { id, count }) => ({ ...obj, [id]: count }), {});