how to Fix undefined variable?

Question

I keep getting this Notice: Undefined variable: previouspage in /var/www/html/ies.aacrao.org/apply/copies.php on line 7 on this line of code:

if ($previouspage == "copies.php") {
    // _s2 variables are the shipping address for the included copy
    $first_s2 = $_SESSION['first_s2'] =  $_POST['first_s2'];
    $last_s2 = $_SESSION['last_s2'] =  $_POST['last_s2'];
    $email_s2 = $_SESSION['email_s2'] =  $_POST['email_s2'];
    $phone_s2 = $_SESSION['phone_s2'] =  $_POST['phone_s2'];
    $title_s2 = $_SESSION['title_s2'] =  $_POST['title_s2'];
    $office_s2 = $_SESSION['office_s2'] =  $_POST['office_s2']; 
    $institution_s2 = $_SESSION['institution_s2'] =  $_POST['institution_s2'];      
    }

Can anyone give me some pointers on how to fix this issue. All of these variables are supposed to be inserted into a database table and at the moment they are not getting inserted.

Well, the error message says it all. The variable `$previouspage` isn't defined anywhere in your code. — Amal Murali, May 09 '14 at 14:34
"how to Fix undefined variable?" -- Have you tried defining it? — Niet the Dark Absol, May 09 '14 at 14:37

Canser Yanbakan · Accepted Answer · 2014-05-09T14:42:31.990

0

if(!empty($previouspage) && $previouspage == "copies.php")

or

if(isset($previouspage) && $previouspage == "copies.php")

I would go with !empty().

By the way, look at these functions.

Empty: http://tr2.php.net/empty

Isset: http://tr2.php.net/isset

Quick explanation:

empty checks for if the variable is defined and has a value, isset just checks if the variable is defined.

edited May 09 '14 at 14:42

answered May 09 '14 at 14:34

Canser Yanbakan

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I'd go with `isset` myself, because you immediately check if it equals a given value. – Niet the Dark Absol May 09 '14 at 14:38
Yes you are right. :) Usually i choose empty why i go with it :) – Canser Yanbakan May 09 '14 at 14:39
I have the same issue in this line of code as well. `if (($previouspage == "copies.php") and ($xtraaddr == 0)) { // set session variable to trigger database work on secondary.php $_SESSION['redirectpage'] = "copies.php"; // redirect to secondary.php header('Location: secondary.php'); }` – user3594109 May 09 '14 at 14:42
Add isset or empty to that line too. Please check my answer again for the explanation. – Canser Yanbakan May 09 '14 at 14:43
Checking for empty will still give you the warning if your variable is not defined. – Oscar M. May 09 '14 at 15:06
No it won't. 'Returns FALSE if var exists and has a non-empty, non-zero value. Otherwise returns TRUE.' – Canser Yanbakan May 09 '14 at 15:09

how to Fix undefined variable?

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