Run results for: boolean flag vs. classList.contains

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36

Browser: Chrome 120

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

bool

1.8M/s

classList

22K/s

View exact numbers

Test name	Executions per second
✓ bool	1,817,902 Ops/sec
classList	22,113 Ops/sec

HTML Preparation code:

<div id="foo" class="test"></div>

Tests:

bool
var element = document.getElementById("foo"); var i = 1000; var check = false; while (i--) { if (check) {} }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { element.classList.contains("test"); }