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

Run details:

User agent: Mozilla/5.0 (Windows NT 6.3; WOW64; Trident/7.0; rv:11.0) like Gecko

Browser: IE 11

Operating system: Windows 8.1

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
undefined	6557759.0 Ops/sec
typeof	11523670.0 Ops/sec
in	12118240.0 Ops/sec
hasOwnProperty	10367980.0 Ops/sec
bool	63299880.0 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;