Run results for: undefined vs. typeof vs. in vs. hasOwnProperty vs Object.prototype.hasOwnProperty

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 11_1_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36

Browser: Chrome 89

Operating system: Mac OS X 11.1.0

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
undefined	4905473.5 Ops/sec
typeof	14294611.0 Ops/sec
in	14311921.0 Ops/sec
hasOwnProperty	12165729.0 Ops/sec
bool	14112100.0 Ops/sec
Object.prototype.hasOwnProperty	2369717.2 Ops/sec

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };
function hasOwn (obj, key) {
  return hasOwnProperty.call(obj, key)
}

Tests: