Some HTML elements have default behaviors. For example, a form submits automatically, and a link opens a new page when clicked.
Sometimes, you want to stop this default behavior and handle the action with JavaScript instead. This is where preventing default actions becomes important.
By using JavaScript, developers can control exactly what happens when users interact with a page.
Why Prevent Default Actions
- To stop form submission for validation
- To prevent page reloads
- To create custom navigation
- To handle links with JavaScript
- To build single-page applications
Preventing default actions gives you full control over user interactions.
This form normally submits and reloads the page when the button is clicked.
JavaScript will be used to stop this behavior and validate the input first.
The preventDefault() method stops the browser’s default action.
Here, it prevents the form from submitting when the input field is empty.
These examples show how JavaScript can stop default browser actions and replace them with custom behavior.
By mastering preventDefault(), students gain the ability to build smooth, controlled, and professional web experiences.