Run results for: Reduce vs Object.assign vs Object.fromEntries

Run details:

User agent: Mozilla/5.0 (iPad; CPU OS 18_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.1 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 18

Operating system: iOS 18.1

Device Platform: Tablet

Date tested: one year ago

From Entries

25K/s

Reduce

18K/s

Map Filter Reduce Assign

13/s

View exact numbers

Test name	Executions per second
✓ From Entries	25,100 Ops/sec
Reduce	18,029 Ops/sec
Map Filter Reduce Assign	13 Ops/sec

Script Preparation code:

function createArray(propsCount) {
    const arr = []
    for (let i = 0; i < propsCount; i += 1) {
        arr.push({
            active: i % 5 === 0
        })
    }
    return arr
}

var users = createArray(1000)

Tests:

Reduce
users.reduce((acc, curr) => { if (curr.active) { return acc } return { ...acc, [curr.id]: curr.name } })
Map Filter Reduce Assign
users.filter((user) => !user.active).map((user) => ({ [user.id]: user.name })).reduce(Object.assign, {})
From Entries
const a = users.filter((user) => !user.active).map((user) => [user.id, user.name]) Object.fromEntries(a)