Run results for: Map vs Object - Insertion, Lookup & Update

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36

Browser: Chrome 137

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 11 months ago

Test name	Executions per second
Map	11.8 Ops/sec
Object	12.4 Ops/sec

Script Preparation code:

const map = new Map();
const obj = {};

const baseKey = '00000000000000000000';

const getKey = (index) => {
  let key = baseKey;

  const chars = [...index.toString()];
  for (let i = 0; i < chars.length; i++) {
    key[i] = chars[i];
  }

  return key;
};

Tests:

Map
for (let i = 0; i < 100000; i++) { const key = getKey(i); map.set(key, 'value'); const _ = map.get(key); map.set(key, 'newValue'); }
Object
for (let i = 0; i < 100000; i++) { const key = getKey(i); obj[key] = 'value'; const _ = obj[key]; obj[key] = 'newValue'; }

Run results for: Map vs Object - Insertion, Lookup & Update

Insertion, Lookup & Update of Map vs Object. Keys length: 20. Loop length: 100000.

Map

Object