classList

Manipulating CSS classes is a common and efficient way to change an element's appearance and state. Instead of directly modifying an element's inline `style` property with JavaScript, it's often better to define styles in your CSS file and then use JavaScript to apply or remove the classes that trigger those styles. The `element.classList` property makes this incredibly easy. It returns a live `DOMTokenList` of the class attributes of the element. This object has several convenient methods. `classList.add('className')` adds one or more classes to the element. `classList.remove('className')` removes them. `classList.toggle('className')` is particularly useful; it adds the class if it's not present and removes it if it is, perfect for things like dropdown menus or dark mode switches. You can also check if an element has a specific class using `classList.contains('className')`, which returns `true` or `false`. Using `classList` is preferable to manipulating the `element.className` string directly because you don't have to worry about parsing the string or accidentally removing other classes. It provides a clean, readable, and robust API for managing an element's classes.