Element: className property
The className
property of the
Element
interface gets and sets the value of the class
attribute
of the specified element.
Value
A string variable representing the class or space-separated classes of the current element.
Examples
js
const el = document.getElementById("item");
el.className = el.className === "active" ? "inactive" : "active";
Notes
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.
Specifications
Specification |
---|
DOM Standard # ref-for-dom-element-classname① |
Browser compatibility
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