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_15_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36

Browser: Chrome 81

Operating system: Mac OS X 10.15.4

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
undefined	5149534.0 Ops/sec
typeof	15373657.0 Ops/sec
in	15314092.0 Ops/sec
hasOwnProperty	13601479.0 Ops/sec
bool	15198382.0 Ops/sec
Object.prototype.hasOwnProperty	2699219.8 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: