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

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/104.0.0.0 Safari/537.36

Browser: Chrome 104

Operating system: Linux

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
undefined	3960782.0 Ops/sec
typeof	12806670.0 Ops/sec
in	12940530.0 Ops/sec
hasOwnProperty	10735070.0 Ops/sec
bool	11582910.0 Ops/sec
Object.prototype.hasOwnProperty	2219791.0 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: