Run results for: compare the ways to generate an array filled with empty objects for iteration

- Array.push - Array.apply: Array.apply(null, Array(100)) - Destructuring operator: [...Array(100)] - Array.prototype.fill Array(100).fill(undefined) - Array.from Array.from({ length: 100 })

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Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/132.0.0.0 Safari/537.36

Browser: Chrome 132

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
✓ Array(n).fill(null)	386,269 Ops/sec
[...Array(n)]	375,067 Ops/sec
Array.push	325,621 Ops/sec
Array with length + push	262,179 Ops/sec
Array.apply(null, Array(n))	245,904 Ops/sec
Array.from({ length: n })	40,169 Ops/sec
Array.from({ length:n }, (item, i) => i)	34,888 Ops/sec

Test name

Executions per second

✓ Array(n).fill(null)

386,269 Ops/sec

[...Array(n)]

375,067 Ops/sec

Array.push

325,621 Ops/sec

Array with length + push

262,179 Ops/sec

Array.apply(null, Array(n))

245,904 Ops/sec

Array.from({ length: n })

40,169 Ops/sec

Array.from({ length:n }, (item, i) => i)

34,888 Ops/sec

Tests:

Array.apply(null, Array(n))
Array.apply(null, Array(1000)).map((item, i) => {});
[...Array(n)]
[...Array(1000)].map((item, i) => {});
Array(n).fill(null)
Array(1000).fill(null).map((item, i) => {});
Array.from({ length: n })
Array.from({ length: 1000 }).map((item, i) => {});
Array.from({ length:n }, (item, i) => i)
Array.from({ length:1000 }, (item, i) => {});
Array.push
const arr = [] for (let i = 0; i < 1000; ++i) arr.push({})
Array with length + push
const arr = new Array(1000); for (let i = 0; i < 1000; ++i) arr.push({})