Run results for: undefined vs. typeof vs. in vs. hasOwnProperty 3 - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko

Browser: IE 11

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
undefined	12565047.0 Ops/sec
typeof	19883026.0 Ops/sec
in	19050872.0 Ops/sec
hasOwnProperty	17159602.0 Ops/sec
bool	75355136.0 Ops/sec
again	12572687.0 Ops/sec

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;
again
undefined !== obj.d;