Run results for: Map vs Object - the real test

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.107 Safari/537.36

Browser: Chrome 92

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Map lookup	12543845.0 Ops/sec
Obj lookup	12508317.0 Ops/sec
Map set	1067563.8 Ops/sec
Obj set	769523.1 Ops/sec
hasOwnProperty	11279075.0 Ops/sec
has	12627165.0 Ops/sec

Script Preparation code:

var map1 = new Map();
var obj1 = {};

map1.set(0, 5);
obj1[0] = 5;

var map2 = new Map();
var obj2 = {};
var arrString = [];
for (var i = 0; i < 10000000; i++) {
  arrString.push(i);
}
var arr = [1,2,3,null,5];
var a = 0, b = 0, c = 0, d = 0;

Tests:

Map lookup
map1.get('aaa');
Obj lookup
obj1['aaa'];
Map set
map2.set(arrString[a++], 1);
Obj set
obj2[arrString[b++]] = 1;
hasOwnProperty
obj1.hasOwnProperty('aaa');
has
map1.has('aaa');
delete
delete obj2[arrString[c++]];
remove
map2.delete(arrString[d++]);
array lookup
arr[2]

Run results for: Map vs Object - the real test

Lookup of map vs object

Map lookup

Obj lookup

Map set

Obj set

hasOwnProperty

has

delete

remove

array lookup