Run results for: Map vs Object (large number of keys)

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36

Browser: Chrome 76

Operating system: Mac OS X 10.13.4

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
Map lookup	44.7 Ops/sec
Obj lookup	36.4 Ops/sec

Script Preparation code:

var map = new Map();
var obj = {};

var i = 0, count = 10000, a;

for (; i < 100000; i++) {
  map.set('key-' + i, i);
  obj['key-' + i] = i;
}

i = 0;

function getRandomKey() {
  return 'key-' + Math.trunc(Math.random() * 100000);
}

Tests:

Map lookup
for (i = 0; i < count; i++) { a = map.get(getRandomKey()); }
Obj lookup
for (i = 0; i < count; i++) { a = obj[getRandomKey()]; }

Run results for: Map vs Object (large number of keys)

Lookup of map vs object

Map lookup

Obj lookup