Undefined variable: _SESSION when sending variables via post through JavaScript trigger

Question

In my index.php file I call session_start() and set a couple of session variables. In a second PHP file I would like to access these session variables.

Answer 1

you must include

<?php session_start();?>

at the beginning of your document, this will start the SESSION ENGINE and enable you to set session variables (ie. $_SESSION['var1'], $_SESSION['var2'], etc)

If you're wanting to get values from a $_POST you could relate the two together by :

$_SESSION['var1'] = $_POST['answer1']

Answer 2

Add the following code to the file browse.php:

error_reporting( error_reporting() & ~E_NOTICE );
if( ! ini_get('date.timezone') )
{
    date_default_timezone_set('GMT');
}
if (version_compare(PHP_VERSION, '5.4.0', '<')) {
    if(session_id() == '') {session_start();}
} else  {
   if (session_status() == PHP_SESSION_NONE) {session_start();}
}   

It will work fine.

Answer 3

I came faced with this problem, and after trying a lot of things, I just included session_start() on the second script and it worked.

Answer 4

I also encountered the same problem recently. I could not access the contents of the $_SESSION variable.

1) This was as a result of trying to access the $_SESSION variable before the declaration of session_start(); In my own case, I had already started a session in a header.php file. But I was accessing the $_SESSION variable before the include statement. Example;

<?php
 $username = $_SESSION['username'];
 //do some logical operation!!!
?> 
<?php include("header.php");?>

instead of doing something like this

<?php include("header.php");?>
<?php
 $username = $_SESSION['username'];
 //do some logical operation!!!
?> 

2) Another thing that may cause this problem, maybe a failure to start a session at the top of all the files that may require access to the $_SESSION variable using

session_start();

Hope this helps anybody that stumbles on the same problem. Although this is coming at a late hour.

Answer 5

There's nothing special whatsoever about POST requests and sessions.
You just need to call session_start at the top of every file request you want to use sessions in, that's it.

Try again with that in mind, it ought to work.

Answer 6

session_start() is the answer. And here's one more way of going about it:

<?php 
if (session_id() == "") 
    session_start();    ?>

This will ensure that a new session is started only if you do not have a current session on already. And ofcourse, as others have said, make sure to place this at the top of the html.