Run results for: instanceof vs in

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:144.0) Gecko/20100101 Firefox/144.0

Browser: Firefox 144

Operating system: Windows

Device Platform: Desktop

Date tested: 9 months ago

in test

3898.1M/s

instanceof test

352.5M/s

View exact numbers

Test name	Executions per second
✓ in test	3,898,128,896 Ops/sec
instanceof test	352,450,752 Ops/sec

Script Preparation code:

class ClassFoo {
    constructor() {
        this.bar = 1;
    }
}

var Foo = ClassFoo;
var foo = new Foo();

Tests: