How can I check a input field exists in the form when I submit it to the server?

Question

How can I check a input field exists in the form when I submit it to the server?

For instance, I want to check whether a check box named 'mem_follow' exists or not in the form.

Or do I have to use javascript (jquery)?

Answer 1

I'm guessing you need to check on the server side after the form is submitted. If that's the case, you can check like so...

<?php
if (isset($_POST['mem_follow']))
{
    // Work your server side magic here
} else {
    // The field was not present, so react accordingly
}
?>

Hope this helps!