variables that change session variables

[sentinel]

Hi, I'm currently writing a mulit-page form app that uses a session to
retain data from each form element in order for the user to jump
between pages, then the final data is passed to a calculation script.

However, I've noticed that if I assign a session variable to another
variable, which then performs a mathematical calculation, the session
variable changes.

i.e. $_SESSION["inflation"] = 4;


$temp_inf = $_SESSION["inflation"];
if ($_SESSION["inflation"] =="RPI") {
$inflation = $rpi;}
else {$inflation = ($temp_inf/100.0);}


now it equals = 0.04

How can I take a value from a session and perform operations on it
without altering the original session value.


Rgds
Neil.

[Per Gustafsson]

Re: variables that change session variables

sentinel wrote:[color=blue]
> However, I've noticed that if I assign a session variable to another
> variable, which then performs a mathematical calculation, the session
> variable changes.
>
> i.e. $_SESSION["inflation"] = 4;
>
>
> $temp_inf = $_SESSION["inflation"];
> if ($_SESSION["inflation"] =="RPI") {
> $inflation = $rpi;}
> else {$inflation = ($temp_inf/100.0);}
>
>
> now it equals = 0.04
>
> How can I take a value from a session and perform operations on it
> without altering the original session value.[/color]

This happends because you have the register_global s directive turned on
and thus, $_SESSION['inflation'] and $inflation contain the same value
and if you manipulate one the other changes as well.

There's two solutions to your problem, either change your naming (i.e.
switch from $_SESSION['inflation'] to $_SESSION['foo'] or from
$inflation to $bar) or turn register_global s off.


Per Gustafsson

--

http://www.pergustafsson.com/