Run results for: JavaScript Array Shallow Copy: Array.from vs Spread Syntax vs Array.prototype.slice vs Array.prototype.concat

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/147.0.0.0 Safari/537.36

Browser: Chrome 147

Operating system: Windows

Device Platform: Desktop

Date tested: 3 months ago

Array.prototype.concat

8.3M/s

Array.prototype.slice

8.2M/s

Spread Syntax

8.1M/s

Array.from

7.0M/s

For Loop Assign

801K/s

For Loop Push

265K/s

View exact numbers

Script Preparation code:

const array = [];
for (let i = 0; i < 1024; i++)
  array.push(i);

Tests:

Array.from
const a = Array.from(array);
Spread Syntax
const a = [...array];
Array.prototype.slice
const a = array.slice();
Array.prototype.concat
const a = array.concat();
For Loop Push
const a = []; for (const i of array) a.push[i];
For Loop Assign
const a = new Array(array.length); for (let i = 0; i < a.length; i++) a[i] = array[i];