How to validate a single checkbox using PHP & MySQL

Question

I was wondering how can I validate a single checkbox using PHP and MySQL.

Here is the HTML.

Answer 1

If isset($_REQUEST['privacy_policy']) returns true, they ticked the box. If not, they didn't.

Answer 2

Although you have asked for PHP validation, you should probably provide javascript validation on the client site as well as PHP validation. This provides a more rapid response than server side validation.

It's important to have both because

• users may not have javascript turned on
• you can't trust anything from the client side anyway :)

If you're using jQuery for anything else, the jQuery Validation plugin makes client side validation very straightforward.