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

Run details:

User agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.93 Safari/537.36

Browser: Chrome 90

Operating system: Linux

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
undefined	3281392.0 Ops/sec
typeof	11782590.0 Ops/sec
in	15453640.0 Ops/sec
hasOwnProperty	14040610.0 Ops/sec
truthy	15898600.0 Ops/sec
local undef	7587859.0 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;