Element: className property
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
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
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 easier to get/set the
class attribute 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.
elm.setAttribute("class", "my-class");
const myClass = elm.getAttribute("class");
Note:
class is the name of an HTML Attribute, while
className is the name of a DOM Property.
Specifications
| Specification |
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| DOM # ref-for-dom-element-classname① |
Browser compatibility
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Legend
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- Full support
- Full support
- Partial support
- Partial support
- Has more compatibility info.