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:102.0) Gecko/20100101 Firefox/102.0

Browser: Firefox 102

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
undefined	1242571000.0 Ops/sec
typeof	1227589000.0 Ops/sec
in	1214152000.0 Ops/sec
hasOwnProperty	1210288000.0 Ops/sec
bool	1215403000.0 Ops/sec
Object.prototype.hasOwnProperty	2374956.0 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: