Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

PHP Enhancing a Simple PHP Application Integrating Validation Errors Setting an Error Message Variable

Bob Sutherton
Bob Sutherton
20,160 Points
Posted by Bob Sutherton
Bob Sutherton
20,160 Points

Why do we need to keep that last exit command? It seems to work fine without it.

When the exit command is removed it works just fine. Why do we need to keep it?

if($mail->Send()) {
            header('Location: contact.php?status=thanks');
            exit;
        } else {
            $error_message = "Shiyat! " . $mail->ErrorInfo;
        }
Jason Cawood
Jason Cawood
6,296 Points

The simple answer is: if you have any other code following that if block, you wouldn't want to run it since you are redirecting with the header function.

Bob Sutherton
Bob Sutherton
20,160 Points
Bob Sutherton
Bob Sutherton
20,160 Points

I know that's what he said in the video but as I said it works fine without it. The contact form doesn't come up when I submit the form, only the thank you message does.

Jason Cawood
Jason Cawood
6,296 Points

What you don't see, is the code has the potential to still run even though the page was redirected. When you add the exit command it ensures that nothing else on the page gets executed.

Bob Sutherton
Bob Sutherton
20,160 Points
Bob Sutherton
Bob Sutherton
20,160 Points

I see what you are saying. What I don't see is that actually happening before my eyes. Are you saying it is just a precaution? Or is the code still getting executed behind the scenes and just not showing up in the browser?

Jason Cawood
Jason Cawood
6,296 Points

right, I gather in your case you are simply displaying something to the screen and that is pretty harmless but rest of the page will still be served by PHP and can be looked at by the client by simply preventing the header command from executing.

That is easy enough to test with a command-line client like wget, for example, by simply telling it not to follow redirects.

So, If you don't prevent it, PHP will send out the whole body even after a header call. That body is fully available to the recipient without any special hacking skills.

1 Answer

Jason Cawood
Jason Cawood
6,296 Points
Jason Cawood
Jason Cawood
6,296 Points

Yes! always... If you don't prevent it, PHP will send out the whole body even after a header call. That body is fully available to the recipient without any special hacking skills.