event.preventDefault() is not a standalone function; rather, it is a method that belongs to the Event object in JavaScript. The purpose of event.preventDefault() is to prevent the default behavior associated with a particular event. When handling events in web development, such as a form submission , link clicks, or key presses. The browser has default behaviors associated with those events. event.preventDefault() is used within event handlers to stop the browser from executing its default action.

Here's a step-by-step examples to illustrate the role of event.preventDefault() :


<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Event Prevention Example</title>
</head>
<body>

    <a href="https://www.example.com" id="example-link">Visit Example.com</a>

    <script>
        document.addEventListener('DOMContentLoaded', function () {
            const exampleLink = document.getElementById('example-link');

            exampleLink.addEventListener('click', function (event) {
                event.preventDefault(); // Prevent the default action (navigating to the link)

                // Your custom logic here
                console.log('Link click prevented. Custom logic executed.');
            });
        });
    </script>

</body>
</html>

In this example, there is a link with the id 'example-link'. When the link is clicked, the default behavior is to navigate to the URL specified in the href attribute. However, the event listener attached to the link prevents this default behavior using event.preventDefault();.
Instead of navigating to the link, the event listener logs a message to the console and executes any custom logic you might add. This allows you to handle the click event in a way that suits your application without triggering the default action associated with the link.
So, in a general JavaScript context, event.preventDefault() is a way to take control of the default behavior of an event and provide your own custom behavior.