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:108.0) Gecko/20100101 Firefox/108.0

Browser: Firefox 108

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
undefined	1114666000.0 Ops/sec
typeof	1297282000.0 Ops/sec
in	1141858000.0 Ops/sec
hasOwnProperty	1068281000.0 Ops/sec
bool	1295866000.0 Ops/sec
Object.prototype.hasOwnProperty	2602873.0 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: