Events

Event handling is the cornerstone of interactivity in web applications. Events are actions or occurrences that happen in the browser, suchas a user clicking a button, pressing a key, moving the mouse, or submitting a form. JavaScript allows you to 'listen' for these events and execute a block of code (an 'event handler' or 'event listener') in response. The modern and recommended way to handle events is by using the `addEventListener()` method. This method is called on the target element (e.g., a button) and takes two main arguments: the type of event to listen for (like `'click'`, `'mouseover'`, or `'keydown'`) and a function to be executed when the event occurs. This approach is flexible because you can add multiple listeners for the same event to a single element. When an event occurs, the browser creates an `event` object that contains information about the event, such as the mouse coordinates for a mouse event or the key that was pressed for a keyboard event. This object is automatically passed as an argument to your event handler function, allowing you to access these details. Understanding the concept of event propagation (bubbling and capturing) is also important for more complex scenarios, as it determines the order in which event handlers are executed when events occur on nested elements. `event.stopPropagation()` can be used to prevent an event from bubbling up the DOM tree.