Run results for: undefined vs typeof vs in vs hasOwnProperty vs bool

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

typeof

18.9M/s

optional chaining undefined

18.9M/s

18.7M/s

bool

18.6M/s

hasOwnProperty

17.7M/s

undefined

10.0M/s

Object.hasOwnProperty

9.3M/s

View exact numbers

Test name	Executions per second
✓ typeof	18,914,318 Ops/sec
optional chaining undefined	18,910,246 Ops/sec
in	18,712,574 Ops/sec
bool	18,642,852 Ops/sec
hasOwnProperty	17,650,708 Ops/sec
undefined	9,955,479 Ops/sec
Object.hasOwnProperty	9,341,534 Ops/sec

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };

Tests: