The className
property of the Element
interface gets and sets the value of the class
attribute of the specified element.
The className
property of the Element
interface gets and sets the value of the class
attribute of the specified element.
A string variable representing the class or space-separated classes of the current element.
js
const el = document.getElementById("item"); el.className = el.className === "active" ? "inactive" : "active";
The name className
is used for this property instead of class
because of conflicts with the "class" keyword in many languages which are used to manipulate the DOM.
className
can also be an instance of SVGAnimatedString
if the element
is an SVGElement
. It is better to get/set the className
of an element using Element.getAttribute
and Element.setAttribute
if you are dealing with SVG elements. However, take into account that Element.getAttribute
returns null
instead of ""
if the element
has an empty class
attribute.
js
elm.setAttribute("class", elm.getAttribute("class"));
Note: The class
is an HTML Attribute, while the className
is a DOM Property.
Specification |
---|
DOM Standard # ref-for-dom-element-classname① |
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | |
className |
22 | 12 | 1 | 5 | 8 | 1 | 4.4 | 25 | 4 | 10.1 | 1 | 1.5 |
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https://developer.mozilla.org/en-US/docs/Web/API/Element/className