HTML DOM classList Propery

< Element Object

Example

Add the "mystyle" class to a <div> element:

document.getElementById("myDIV").classList.add("mystyle");

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More "Try it Yourself" examples below.

Definition and Usage

The classList property returns the class name(s) of an element, as a DOMTokenList object.

This property is useful to add, remove and toggle CSS classes on an element.

The classList property is read-only, however, you can modify it by using the add() and remove() methods.

Cross-browser solution: The classList property is not supported in IE9 and earlier. However, you can use the className property or regular expressions for a cross-browser solution (see "More Examples" on the bottom of this page).

Browser Support

The numbers in the table specify the first browser version that fully supports the property.

Property
classList	8.0	10.0	3.6	5.1	11.5

Syntax

element.classList

Properties

Property	Description
length	Returns the number of classes in the list. This property is read-only

Methods

Method	Description
add(class1, class2, ...)	Adds one or more class names to an element. If the specified class already exist, the class will not be added
contains(class)	Returns a Boolean value, indicating whether an element has the specified class name. Possible values: true - the element contains the specified class name false - the element does not contain the specified class name
item(index)	Returns the class name with a specified index number from an element. Index starts at 0. Returns null if the index is out of range
remove(class1, class2, ...)	Removes one or more class names from an element. Note: Removing a class that does not exist, does NOT throw an error
toggle(class, true\|false)	Toggles between a class name for an element. The first parameter removes the specified class from an element, and returns false. If the class does not exist, it is added to the element, and the return value is true. The optional second parameter is a Boolean value that forces the class to be added or removed, regardless of whether or not it already existed. For example: Remove a class: element.classList.toggle("classToRemove", false); Add a class: element.classList.toggle("classToAdd", true); Note: The second parameter is not supported in Internet Explorer or Opera 12 and earlier.

Technical Details

Return Value:	A DOMTokenList, containing a list of the class name(s) of an element

More Examples

Example

Add multiple classes to a <div> element:

document.getElementById("myDIV").classList.add("mystyle", "anotherClass", "thirdClass");

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Example

Remove a class from a <div> element:

document.getElementById("myDIV").classList.remove("mystyle");

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Example

Remove multiple classes from a <div> element:

document.getElementById("myDIV").classList.remove("mystyle", "anotherClass", "thirdClass");

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Example

Toggle between two classes for a <div> element:

document.getElementById("myDIV").classList.toggle("newClassName");

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Example

Get the class name(s) of a <div> element:

<div id="myDIV" class="mystyle anotherClass thirdClass">I am a DIV element</div>

var x = document.getElementById("myDIV").classList;

The result of x will be:

mystyle anotherClass thirdClass

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Example

Find out how many class names a <div> element has:

var x = document.getElementById("myDIV").classList.length;

The result of x will be:

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Example

Get the first class name (index 0) of a <div> element:

var x = document.getElementById("myDIV").classList.item(0);

The result of x will be:

mystyle

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Example

Find out if an element has a "mystyle" class:

var x = document.getElementById("myDIV").classList.contains("mystyle");

The result of x will be:

true

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Example

Find out if an element has a "mystyle" class. If so, remove another class name:

var x = document.getElementById("myDIV");

if (x.classList.contains("mystyle")) {
x.classList.remove("anotherClass");
} else {
alert("Could not find it.");
}

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Example

Toggle between classes to create a dropdown button:

// Get the button, and when the user clicks on it, execute myFunction
document.getElementById("myBtn").onclick = function() {myFunction()};

/* myFunction toggles between adding and removing the show class, which is used to hide and show the dropdown content */
function myFunction() {
document.getElementById("myDropdown").classList.toggle("show");
}

// Close the dropdown if the user clicks outside of it
window.onclick = function(event) {
if (!event.target.matches('.dropbtn')) {

    var dropdowns = document.getElementsByClassName("dropdown-content");
    var i;
    for (i = 0; i < dropdowns.length; i++) {
      var openDropdown = dropdowns[i];
      if (openDropdown.classList.contains('show')) {
        openDropdown.classList.remove('show');
      }
    }
}
}

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Fallback Example: add

A cross-browser solution when using the classList.add() method, for IE9 and earlier:

var x = document.getElementById("myDIV");

if (x.classList) {
x.classList.add("mystyle");
} else {
x.className = "mystyle"; // For IE9 and earlier
}

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Fallback Example: remove

A cross-browser solution when using the classList.remove() method, for IE9 and earlier:

var x = document.getElementById("myDIV");

if (x.classList) {
x.classList.remove("mystyle");
} else {
x.className = x.className.replace(/\bmystyle/g, ""); // For IE9 and earlier
}

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Fallback Example: contains

A cross-browser solution when using the classList.contains() method, for IE9 and earlier:

var x = document.getElementById("myDIV");

if (x.classList) {
alert(x.classList.contains("mystyle"));
} else {
alert(/\bmystyle/g.test(x.className)); // For IE9 and earlier
}

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Fallback Example: toggle

A cross-browser solution when using the classList.toggle() method, for IE9:

var x = document.getElementById("myDIV");

if (x.classList) {
    x.classList.toggle("mystyle");
} else {
    // For IE9
    var classes = x.className.split(" ");
    var i = classes.indexOf("mystyle");

    if (i >= 0)
        classes.splice(i, 1);
    else
        classes.push("mystyle");
        x.className = classes.join(" ");
}

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CSS Tutorial: CSS Selectors

CSS Reference: CSS .class Selector

HTML DOM Reference: HTML DOM className Property

HTML DOM Reference: HTML DOM getElementsByClassName() Method

HTML DOM Reference: HTML DOM Style Object

< Element Object