Learn how to add a class name to an element with JavaScript. Click the button to add a class to me! Add a class name to the div element with id="myDIV" (in this example we use a button to add the class). This is a DIV element. Style the specified class name: Get the <div> element with id="myDIV" and add the "mystyle" class to it:

Nov 28, 2016 · To add a class to an element, without removing/affecting existing values, append a space and the new classname, like so: document.getElementById("MyElement").className += " MyClass"; To change all classes for an element: To replace all existing classes with one or more new classes, set the className attribute:

3 ways to add a class to a DOM element in JavaScript. There are multiple ways of doing this. I will show you three ways to add classes and clarify some benefits of each way. You can use any given method to add a class to your element, another way to check for, change or remove them.

Dec 20, 2012 · Or, depending on the required browser support, you can use the classList.add() method: https://developer.mozilla.org/en-US/docs/Web/API/Element/classList http://caniuse.com/#feat=classlist. UPDATE: A more elegant solution for referencing the HTML element might be this: FYI, classlist.add/.remove doesn't work on document.documentElement.

JavaScript Classes are templates for JavaScript Objects. Use the keyword class to create a class. Always add a method named constructor(): constructor () { ... The example above creates a class named "Car". The class has two initial properties: "name" and "year". A JavaScript class is not an object. It is a template for JavaScript objects.

Mar 4, 2020 · Learn how to add, remove, and toggle CSS classes in vanilla JavaScript without jQuery by using the classList property.

Mar 20, 2025 · Adding a class to an element using JavaScript is a crucial technique for dynamically modifying web applications, particularly in automated testing scenarios. Classes are often used to apply styles, manage states, or trigger specific behaviors in response to user interactions or test conditions.

Jan 29, 2024 · Learn how to add a class to an element in JavaScript using className, classList, toggle and setAttribute method, with examples.

The JavaScript add class uses addClass() method to add a single or more than one class name to elements. During this process, no existing class attributes are removed because the class names are added to the class attribute.

JavaScript References. W3Schools maintains a complete JavaScript reference, including all HTML and browser objects. The reference contains examples for all properties, methods and events, and is continuously updated according to the …