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

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.4.1 Safari/605.1.15

Browser: Safari 17

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 10 months ago

Test name	Executions per second
Map	21.3 Ops/sec
Object	19.4 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
// 1: insert, lookup & update for (let i = 0; i < 100000; i++) { const key = getKey(i); map.set(key, 'value'); const _ = map.get(key); map.set(key, 'newValue'); } // 2: delete all keys for (let i = 0; i < 100000; i++) { const key = getKey(i); map.delete(key); } // 3: insert, lookup & update again for (let i = 0; i < 100000; i++) { const key = getKey(i); map.set(key, 'value'); const _ = map.get(key); map.set(key, 'newValue'); }
Object
// 1: insert, lookup & update for (let i = 0; i < 100000; i++) { const key = getKey(i); obj[key] = 'value'; const _ = obj[key]; obj[key] = 'newValue'; } // 2: delete all keys for (let i = 0; i < 100000; i++) { const key = getKey(i); delete obj[key]; } // 3: insert, lookup & update again 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 & Deletion

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

Map

Object