Run results for: Converting array to object using Array.reduce(), Object.fromEntries(), Object.assign(), for loop, ...spread

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Array.reduce()

29K/s

For loop

24K/s

Object.fromEntries() + Object.entries()

2K/s

Object ...spread

2K/s

Object.assign()

1K/s

View exact numbers

Test name	Executions per second
✓ Array.reduce()	29,225 Ops/sec
For loop	24,355 Ops/sec
Object.fromEntries() + Object.entries()	2,106 Ops/sec
Object ...spread	1,519 Ops/sec
Object.assign()	1,286 Ops/sec

Script Preparation code:

let array = Array.from({length:4096},(_,i)=>i).sort(() => Math.random() - 0.5)

Tests:

Array.reduce()
let object = array.reduce((pool, item, nth) => { pool[nth] = item; return pool; }, {});
For loop
let object = {}; let length = array.length; for(let i = 0; i < length; i++) { object[i] = array[i]; }
Object.fromEntries() + Object.entries()
let object = Object.fromEntries(Object.entries(array))
Object.assign()
let object = Object.assign({},array)
Object ...spread
let object = {...array}