Run results for: Map vs Object with Number Keys

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.0.0 Safari/537.36

Browser: Chrome 104

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Iterate Object	232.6 Ops/sec
Iterate Map	4175.1 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;

Run results for: Map vs Object with Number Keys

Iterate Object

Iterate Map