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 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36

Browser: Chrome 67

Operating system: Mac OS X 10.10.5

Device Platform: Desktop

Date tested: 6 years ago

Test name	Executions per second
undefined	2651553.0 Ops/sec
typeof	6018463.0 Ops/sec
in	8766487.0 Ops/sec
hasOwnProperty	8479147.0 Ops/sec
bool	9338917.0 Ops/sec
Object.prototype.hasOwnProperty	1559726.0 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: