Run results for: Initializing array with n undefined items

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.77 Safari/537.36 Edg/91.0.864.37

Browser: Chrome 91

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Script Preparation code:

var n = 100000; // 100k

Tests:

[...Array(n).keys()].map(k => undefined)
[...Array(n).keys()].map(k => undefined);
Array.apply(null, { length: 4 })
Array.apply(null, { length: n });
Array.from
Array.from({ length: n }, () => undefined);
Array(n).fill(undefined)
Array(n).fill(undefined)
for loop push
const arr = []; for (let i = 0; i < n; i++) { arr.push(undefined); }