Run results for: Typeof x === 'undefined' vs x === undefined (test without syntax error)

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36

Browser: Chrome 89

Operating system: Windows

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Typeof check	13830228.0 Ops/sec
Strict equality	4480603.5 Ops/sec

Script Preparation code:

var x = undefined;

Tests: