Run results for: JS Map<number, object> vs Array<{ number, object }>

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:132.0) Gecko/20100101 Firefox/132.0

Browser: Firefox 132

Operating system: Ubuntu

Device Platform: Desktop

Date tested: one year ago

Map.get

255.8M/s

Array.findIndex

2K/s

View exact numbers

Test name	Executions per second
✓ Map.get	255,799,296 Ops/sec
Array.findIndex	2,175 Ops/sec

Script Preparation code:


const object = (id) => ({ a: () => id, b: "id-" + id, });

const map = new Map();

const arr = [];

const max = 100_000;

for (let i = 0; i < max; i++) {
  	map.set(i, object(i));
  	arr.push({ id: i, ...object(i) });
}

const rng = () => Math.floor(Math.random() * max);

Tests:

Array.findIndex
const id = rng(); const index = arr.findIndex((obj) => obj.id === id);
Map.get
const id = rng(); const value = map.get(id);