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/67.0.3396.99 Safari/537.36

Browser: Chrome 67

Operating system: Linux

Device Platform: Desktop

Date tested: 6 years ago

Test name	Executions per second
undefined	2940678.2 Ops/sec
typeof	11160445.0 Ops/sec
in	10344433.0 Ops/sec
hasOwnProperty	9902569.0 Ops/sec
bool	11311358.0 Ops/sec
Object.prototype.hasOwnProperty	1803497.5 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: