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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:73.0) Gecko/20100101 Firefox/73.0

Browser: Firefox 73

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
undefined	114588100.0 Ops/sec
typeof	300237900.0 Ops/sec
in	167309000.0 Ops/sec
hasOwnProperty	172127800.0 Ops/sec
bool	300499800.0 Ops/sec
Object.prototype.hasOwnProperty	1372460.0 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: