Run results for: Array.from vs spread vs construct manually

Run details:

User agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:56.0) Gecko/20100101 Firefox/56.0

Browser: Firefox 56

Operating system: Windows 7

Device Platform: Desktop

Date tested: 5 years ago

Script Preparation code:

var src = Object.keys([...Array(10000)]);
var z = {};

Tests:

Array.from
z.z = Array.from(src[Symbol.iterator]());
manual
let n = src.length; let a = Array(n); let iter = src[Symbol.iterator](); for (let i = 0; i < n; ++i) {a[i] = iter.next().value;}; z.z = a;
spread
z.z = [...(src[Symbol.iterator]())];