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_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36

Browser: Chrome 69

Operating system: Mac OS X 10.14.0

Device Platform: Desktop

Date tested: 6 years ago

Test name	Executions per second
undefined	3982222.8 Ops/sec
typeof	13662549.0 Ops/sec
in	12406770.0 Ops/sec
hasOwnProperty	12130380.0 Ops/sec
bool	13799604.0 Ops/sec
Object.prototype.hasOwnProperty	2376845.0 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: