Run results for: void 0 vs undefined vs variable containing undefined

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 15_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/15.5 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 15

Operating system: iOS 15.5

Device Platform: Mobile

Date tested: 2 years ago

void 0

20.7M/s

constant containing undefined

12.2M/s

undefined

8.4M/s

View exact numbers

Test name	Executions per second
✓ void 0	20,734,222 Ops/sec
constant containing undefined	12,156,584 Ops/sec
undefined	8,393,813 Ops/sec

Script Preparation code:

var a = 1, u = void 0;

Tests: