Run results for: Map.has vs Object hasOwnProperty vs direct check v2

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36 Edg/138.0.0.0

Browser: Chrome 138

Operating system: Linux

Device Platform: Desktop

Date tested: one year ago

direct check

3K/s

Map lookup

3K/s

Obj lookup

3K/s

View exact numbers

Test name	Executions per second
✓ direct check	3,248 Ops/sec
Map lookup	3,164 Ops/sec
Obj lookup	3,033 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'); }
direct check
for (i = 0; i < count; i++) { a = obj['stringKey'] != null }

Run results for: Map.has vs Object hasOwnProperty vs direct check v2

Lookup of map vs object

Map lookup

Obj lookup

direct check