Run results for: instanceof vs undefined prop

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:139.0) Gecko/20100101 Firefox/139.0

Browser: Firefox 139

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

checking prop

1412.2M/s

instanceof

68.6M/s

View exact numbers

Test name	Executions per second
✓ checking prop	1,412,223,872 Ops/sec
instanceof	68,608,496 Ops/sec

Script Preparation code:

var obj = {a:2};

Tests: