Run results for: Map vs Object with 100 keys and 1/5 delete on new item

Run details:

User agent: Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/604.1.38 (KHTML, like Gecko) Chrome/49.0.2623 Safari/604.1.38 CoherentGT/2.0

Browser: Chrome 49

Operating system: Windows 8

Device Platform: Desktop

Date tested: 10 months ago

Obj set

154/s

Map set

152/s

View exact numbers

Test name	Executions per second
✓ Obj set	154 Ops/sec
Map set	152 Ops/sec

Script Preparation code:


const nbKeys = 100;
var i = 0, count = 1000, a;
function getRandomInt(max) {
  return Math.floor(Math.random() * max);
}

const deleteFreq = 5;

Tests:

Map set
for( let nbObj = 0; nbObj < 25; nbObj++) { let localmap = new Map(); for (i = 0; i < count; i++) { const deleteOrSet = getRandomInt(deleteFreq) !== 0 if(deleteOrSet) localmap.delete(getRandomInt(nbKeys)); else localmap.set(getRandomInt(nbKeys), getRandomInt(42)); } }
Obj set
for( let nbObj = 0; nbObj < 25; nbObj++) { let localobj = {}; for (i = 0; i < count; i++) { const deleteOrSet = getRandomInt(deleteFreq) !== 0 if(deleteOrSet) delete localobj[getRandomInt(nbKeys)]; else localobj[getRandomInt(nbKeys)] = getRandomInt(42); } }

Run results for: Map vs Object with 100 keys and 1/5 delete on new item

Lookup of map vs object

Map set

Obj set