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

Run details:

User agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:95.0) Gecko/20100101 Firefox/95.0

Browser: Firefox 95

Operating system: Ubuntu

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
undefined	493210600.0 Ops/sec
typeof	543697400.0 Ops/sec
in	540011900.0 Ops/sec
hasOwnProperty	479848700.0 Ops/sec
bool	502234600.0 Ops/sec
Object.prototype.hasOwnProperty	693754.7 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: