Run results for: typeof vs undefined

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/80.0.3987.132 YaBrowser/20.3.1.195 Yowser/2.5 Yptp/1.23 Safari/537.36

Browser: Yandex Browser 20

Operating system: Windows

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
typeof str	13202050.0 Ops/sec
typeof var	6199159.0 Ops/sec
real undefined	4267246.0 Ops/sec

Script Preparation code:

var x;
var und = 'unde';
und += 'fined'

Tests:

typeof str
typeof x==='undefined'
typeof var
typeof x === und;
real undefined
x === undefined

Run results for: typeof vs undefined

typeof str

typeof var

real undefined