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

Run details:

User agent: Mozilla/5.0 (Linux; Android 12; SM-N9750) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.73 Mobile Safari/537.36

Browser: Chrome Mobile 99

Operating system: Android

Device Platform: Mobile

Date tested: 2 years ago

Test name	Executions per second
undefined	3402067.0 Ops/sec
typeof	9815393.0 Ops/sec
in	9849718.0 Ops/sec
hasOwnProperty	8950236.0 Ops/sec
bool	9839643.0 Ops/sec
Object.prototype.hasOwnProperty	1570372.0 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: