Run results for: in vs not undefined

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:101.0) Gecko/20100101 Firefox/101.0

Browser: Firefox 101

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
undefined	934878600.0 Ops/sec
in	1020791000.0 Ops/sec

Script Preparation code:

var obj = { a: 1, b: 2, c: 3, d: 4, e: 5 };

Tests: