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

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/61.0.3163.100 Safari/537.36

Browser: Chrome 61

Operating system: Windows

Device Platform: Other

Date tested: 6 years ago

Test name	Executions per second
undefined	1728544.0 Ops/sec
typeof	4062518.0 Ops/sec
in	3873153.0 Ops/sec
hasOwnProperty	3985097.0 Ops/sec
truthy	4210639.0 Ops/sec
local undef	2376080.0 Ops/sec

Website performance monitoring

Script Preparation code:

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

Tests:

undefined
undefined !== obj.d;
typeof
'undefined' !== typeof obj.d;
in
'd' in obj;
hasOwnProperty
obj.hasOwnProperty( 'd' );
truthy
!! obj.d;
local undef
undef !== obj.d;