Run results for: Undefined testing including ! - MeasureThat.net

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.1 Safari/605.1.15

Browser: Safari 16

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
typeof x === "undefined"	28805922.0 Ops/sec
x === undefined	10539086.0 Ops/sec
x == undefined	10468040.0 Ops/sec
x == null	29097300.0 Ops/sec
!x	29059010.0 Ops/sec

Script Preparation code:

var x;

Tests:

typeof x === "undefined"
typeof x === "undefined"
x === undefined
x === undefined
x == undefined
x == undefined
x == null
x == null
!x
!x