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) Ubuntu Chromium/73.0.3683.86 Chrome/73.0.3683.86 Safari/537.36

Browser: Chromium 73

Operating system: Ubuntu

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
undefined	2547806.0 Ops/sec
typeof	8566786.0 Ops/sec
in	7205110.5 Ops/sec
hasOwnProperty	7270888.0 Ops/sec
bool	8334868.5 Ops/sec
Object.prototype.hasOwnProperty	1599361.2 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: