HTML DOM classList Property
Element Object
Example
Add the "mystyle" class to a
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
Example
Remove a class from a
Example
Remove multiple classes from a
Example
Toggle between two classes for a
Example
Get the class name[s] of a
var x = document.getElementById["myDIV"].classList; Try it Yourself »
Example
Find out how many class names a
Example
Get the first class name [index 0] of a
Example
Find out if an element has a "mystyle" class: var x = document.getElementById["myDIV"].classList.contains["mystyle"]; Try it Yourself »
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."];
}Try it Yourself »
Example
Toggle between classes to create a dropdown button: // Get the button, and when the user clicks on it, execute myFunction
document.getElementById["myBtn"]. title = 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"];
}
Try it Yourself »
Fallback Example: add
A cross-browser solution when using the classList.add[] method, for IE9 and earlier: var x, name, arr;
x = document.getElementById["myDIV"];
if [x.classList] {
x.classList.add["mystyle"];
} else {
name = "mystyle";
arr = x.className.split[" "];
if [arr.indexOf[name] == -1] {
x.className += " " + name;
}
}Try it Yourself »
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\b/g, ""]; // For IE9 and earlier
}Try it Yourself »
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\b/g.test[x.className]]; // For IE9 and earlier
}Try it Yourself »
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[" "];
}Try it Yourself »
Example
Create a sticky navigation bar: // Get the navbar
var navbar = document.getElementById["navbar"];
// Get the offset position of the navbar
var sticky = navbar.offsetTop;
// Add the sticky class to the navbar when you reach its scroll position. Remove the sticky class when you leave the scroll position.
function myFunction[] {
if [window.pageYOffset >= sticky] {
navbar.classList.add["sticky"]
} else {
navbar.classList.remove["sticky"];
}
}
Try it Yourself »
Related Pages
CSS Tutorial: CSS Syntax
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