Run results for: undefined vs. typeof vs. in vs. operator

Object lookup performance

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Run details:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36
Chrome 125
Windows
Desktop
2 years ago
typeof
9.8M/s
in
9.7M/s
operator
9.7M/s
bool
9.2M/s
undefined
3.9M/s
View exact numbers
Test name Executions per second
✓ typeof 9,829,193 Ops/sec
in 9,710,331 Ops/sec
operator 9,667,523 Ops/sec
bool 9,238,418 Ops/sec
undefined 3,892,559 Ops/sec
Script Preparation code:
Tests: