Run results for: jsj undefined vs. typeof vs. in vs. hasOwnProperty - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.75 Safari/537.36

Browser: Chrome 73

Operating system: Mac OS X 10.14.3

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
undefined	4648858.0 Ops/sec
typeof	14641500.0 Ops/sec
in	13467060.0 Ops/sec
hasOwnProperty	13059520.0 Ops/sec
bool	14518370.0 Ops/sec
undefined2	14556750.0 Ops/sec

Website performance monitoring

Script Preparation code:

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

Tests:

undefined
undefined === obj.d;
typeof
'undefined' === typeof obj.d;
in
!('d' in obj);
hasOwnProperty
!obj.hasOwnProperty( 'd' );
bool
! obj.d;
undefined2
typeof obj.d === 'undefined';