Required Input

Some inputs must be filled in: for example, you can't sign up for a course without a name or a password.

<input type="text" name="nickname" id="input-nickname" required>

To make an input required, we just add the required attribute. Like the controls attribute of videos, it has no value: it's enough to write it. When the user tries to send the form with a required input empty, the browser doesn't send it and shows a message instead.