problem with if statement

[psychohagis]

I have the following if statement:

 

if ($_SESSION['rank']!='webmaster' OR $_SESSION['rank']!='chairman' OR $_SESSION['rank']!='secretary' OR $_SESSION['rank']!='treasurer')
{
exit('<meta http-equiv=refresh content=0;URL=http://www.MYSITE.org.uk/events.php>');
}

 

I dumped the variable $_SESSION['rank'] and it came out as "webmaster" but I still get redirected away?

 

Can anyone help?

[Orio]

Change the or to and.

 

Orio.

[psychohagis]

Why would that work?

[papaface]

It wouldnt. Do you have session_start(); at the top of the page?

[psychohagis]

Well i tried that and it works but i dont understand why.

 

Surely AND would require all of them to evaluate to true where as OR only needs one of them to evaluate to true - which makes more sense to me because $_SESSION['rank'] can't have multiple values.

[papaface]

You are correct.

Maybe Orio can shed some light.

[designationlocutus]

Might be good to go with the switch statement on this one

[Orio]

events.php is for authorized users, or unauthorized? If it's for authorized, then you need to keep the OR, but it seemed to me it's for unauthorized users.

Now, for the session_start() part, you need to use that because if you don't use it the $_SESSION array is not restored. Every time you want to use the $_SESSION array, make sure you call session_start().

 

Orio.

[psychohagis]

yh ive got session_start() on every page.

 

events.php is for both authorised and unauthorised users depending on what part of it youre in. 

 

I just dont see the logic behind using AND when i only need one of the statements to evaluate to true

[designationlocutus]

If you use the switch statement, you could do something like:

 

<?php
session_start();

$rank = $_SESSION['rank'];

switch ($rank) {

case "webmaster":
case "chairman":
case "secretary":
case "treasurer":
// Do whatever
break;

default:
exit('<meta http-equiv=refresh content=0;URL=http://www.MYSITE.org.uk/events.php>');
}
?>