Run results for: Map.has vs Object hasOwnProperty

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 26_0_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) CriOS/141.0.7390.41 Mobile/15E148 Safari/604.1

Browser: Chrome Mobile iOS 141

Operating system: iOS 26.0.1

Device Platform: Mobile

Date tested: 10 months ago

Obj lookup

669K/s

Map lookup

498K/s

View exact numbers

Test name	Executions per second
✓ Obj lookup	668,528 Ops/sec
Map lookup	497,526 Ops/sec

Script Preparation code:

var map = new Map();
var obj = {};

var j = 0;
while (j < 10000) {
  var key = "Key_" + j;
  map.set(key, 5);
  obj[key] = 5;
  j += 1;
}

var stringKey = 'asdfasdjfa;sjfjaklfjklsjklajjjj;jlsjfajdfsfjs;fjsfka';

var i = 0, count = 1000, a;

Tests:

Map lookup
for (i = 0; i < count; i++) { a = map.has('stringKey'); }
Obj lookup
for (i = 0; i < count; i++) { a = obj.hasOwnProperty('stringKey'); }

Run results for: Map.has vs Object hasOwnProperty

Lookup of map vs object

Map lookup

Obj lookup