an &quot;exit&quot; syntax question

an "exit" syntax question

Anon

I have a page that does a whole bunch of stuff, until the visitor clicks a form button. The form submits to itself ($php_self).

If it's submitted, the entire php page is totally completely replaced by another entire php page (html, head, body, everything!).

I've found that it is NOT necessary to include "exit" after the "include" function. Should I go ahead and put that "exit" in anyway?

Here are my "technical-and-obsessively perfectionistic" questions:

1.) Is the following gramattically syntaxically correct?

2.) do I need the "else" in there if I have the "exit".... or, is the purpose of the "exit" so I don't have to put the "else" in there

Here's the code:

<?php
if (isset($formbutton)) {
include('./next_page.php');
exit;
}
else
{
?>
<head></head><body>etc., etc.
<?php
}
?>

And, finally, How should I know whether and to do reverse statements? For example, my code above starts with if(isset($formbutton))..... I could easily start it with if(!isset($formbutton)) .....

if I do that, would it make the php go thru my entire page to get to where it's supposed to? does php work like that?

Thanks!

mrmufin

First, you don't need the else clause after an exit. Anything after an exit just won't happen.

What order to check stuff in is largely an element of programming style; it's more important to have a method and use it consistently than to do things arbitrarily.

My general theory is "weed out any and all errors, starting with the most critical errors (ones that should trigger an exit, like we couldn't connect to the database engine), continue through with silly-ass user errors (your passwords don't match, etc), then once all that has been done, do yer stuff". That's just my approach. Right, wrong or indifferent, it's the approach I use and I use it consistently.

Anon

To continue what mrmufin said...

If the else{} is dropped, then the exit() becomes necessary.

Myself, I would use the exit to save a bit of runtime. Without it, PHP will skip over the else{} block, as advertised, and continue running the code and outputting the HTML following it (even if it is just a newline that nobody really gives a toss about). The other advantage of having the exit is self-documentation - it makes it quite explicit to anyone reading the code that it is a point where execution ends - that nothing more will happen from that point on (especially after the else{} block).