Run results for: test Map vs Object with string which use string as key and value

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64; rv:139.0) Gecko/20100101 Firefox/139.0

Browser: Firefox 139

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

Benchmark engine: Benchmark.js

Map get

48K/s

Obj get

9K/s

Obj set

7K/s

Map set

7K/s

View exact numbers

Test name	Executions per second
✓ Map get	48,445 Ops/sec
Obj get	8,982 Ops/sec
Obj set	7,148 Ops/sec
Map set	6,869 Ops/sec

Script Preparation code:

const map = new Map();
const obj = {};

function generateKeys(startIndex, endIndex) {
  const res = [];
  for (let i = startIndex; i < endIndex; i++) {
    res.push(btoa(i));
  }

  return res;
}

const kvs = generateKeys(0, 1000);
const newKvs = generateKeys(10000, 12000);

kvs.forEach(kv => {
  map.set(kv, kv);
  obj[kv] = kv;
});

Tests:

Map get
kvs.forEach(kv => { map.get(kv); });
Obj get
kvs.forEach(kv => { obj[kv]; });
Map set
kvs.forEach(kv => { map.set(kv, kv); });
Obj set
kvs.forEach(kv => { obj[kv] = kv; });