Run results for: undefined vs. typeof vs. in vs. hasOwnProperty

Run details:

User agent: Mozilla/5.0 (Linux; arm_64; Android 13; RMX3151) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 YaSearchBrowser/23.71.1 BroPP/1.0 YaSearchApp/23.71.1 webOmni SA/3 Mobile Safari/537.36

Browser: Chrome 114

Operating system: Android

Device Platform: Mobile

Date tested: one year ago

Test name	Executions per second
undefined	2764604.2 Ops/sec
typeof	7957991.0 Ops/sec
in	7965982.0 Ops/sec
hasOwnProperty	7141948.0 Ops/sec
bool	7943663.0 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;

Run results for: undefined vs. typeof vs. in vs. hasOwnProperty

Object lookup performance

undefined

typeof

in

hasOwnProperty

bool