Run results for: Map vs preallocation

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:125.0) Gecko/20100101 Firefox/125.0

Browser: Firefox 125

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Preallocation

185/s

Map

161/s

View exact numbers

Test name	Executions per second
✓ Preallocation	185 Ops/sec
Map	161 Ops/sec

Script Preparation code:

var array = new Array(1000000).fill(0);

Tests:

Map
const array2 = array.map((item, index) => index);
Preallocation
const array2 = new Array(1000000).fill(0); for (let i = 0; i < array2.length; i++) array2[i] = i;