Run results for: instanceof vs undefined prop

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36

Browser: Chrome 137

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

instanceof

92.4M/s

checking prop

91.7M/s

View exact numbers

Test name	Executions per second
✓ instanceof	92,448,728 Ops/sec
checking prop	91,692,416 Ops/sec

Script Preparation code:

var obj = {a:2};

Tests: