Run results for: Map vs Object with Number Keys

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0

Browser: Firefox 140

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Iterate Map

1K/s

Iterate Object

296/s

View exact numbers

Test name	Executions per second
✓ Iterate Map	1,061 Ops/sec
Iterate Object	296 Ops/sec

Script Preparation code:

var object = Object.fromEntries(new Array(100000).fill(1).map((_, i) => [Math.random() * 100000 | 0, 'value']));
var map = new Map(Object.entries(object));

Tests:

Iterate Object
let lastValue = ''; for (var key in object) lastValue = object[key];
Iterate Map
let lastValue = ''; for (var [key, value] of map) lastValue = value;