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PHP Build a Simple PHP Application Integrating with PayPal Redirecting Invalid Shirt IDs

Posted by Luca Vicini
Luca Vicini
Courses Plus Student 8,594 Points

exit(); after header("Location: shirts.php"); is it really necessary?

I am wondering why we need to place an exit(); command after the header instruction. If execution is passed to shirts.php why do we need the exit(); anyway?

3 Answers

David Omar
David Omar
5,676 Points
David Omar
David Omar
5,676 Points

exit() terminates the current script. My basic understanding of it is that the header function doesn't immediately terminate the connection and the code after can still be executed. So adding exit after header is to make sure that code after it won't be executed. I'm sure this isn't the best answer but it's enough of an answer for me.

thomascawthorn
thomascawthorn
22,986 Points

Yeah, that's it! header() will not stop the script and things below will continue to be parsed. If you scroll down to the comments on the php function page for exit(), some people have added hints and tips to make this action a little cleaner... if you feel up for a challenge!

Luca Vicini
PLUS
Luca Vicini
Courses Plus Student 8,594 Points
Luca Vicini
Luca Vicini
Courses Plus Student 8,594 Points

Thanks for your answers!! It's quite interesting. In languages like Java, C or Pascal, exit() or a similar goto() style command is most of the time considered sloppy programming, while in PHP it looks like it's considered normal practice (even a necessity).

I distress here, but I'm still getting used to the weakly typed nature of PHP. Writing something like: $x = 10 + "3"; in PHP gives $x =13; fantastic freedom but prone to extremely sloppy code unless you know exactly how types are going to be converted.

Getting used to all this...

Shawn Gregory
PLUS
Shawn Gregory
Courses Plus Student 40,672 Points
Shawn Gregory
Shawn Gregory
Courses Plus Student 40,672 Points

Hello,

You can also combine the two lines into one since exit() can take a parameter that is performed before the script exits. 

exit(header("Location: index.php"));

Of course in my scripts I use the die() function (which isn't that different from exit()).

Cheers!