Run results for: className vs. classList (comparing and adding)2

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; rv:11.0) like Gecko

Browser: IE 11

Operating system: Windows

Device Platform: Other

Date tested: 2025 years ago

Test name	Executions per second
className	0.0 Ops/sec
classList	1466.6 Ops/sec

HTML Preparation code:

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

Tests:

className
var element = document.getElementById("foo"); var i = 1000; while (i--) { if(element.className.baseVal.indexOf("test") > -1) { element.className.baseVal = "bar"; }else { element.className.baseVal = "test"; } }
classList
var element = document.getElementById("foo"); var i = 1000; while (i--) { if(element.classList.contains("test")) { element.classList.add("bar"); } else { element.classList.add("test"); } }