PHP variable in session variable

Question

I am trying to use a session variable like this:

$string = 'abc';    
$_SESSION[$string];

But I get access if i use it like this:

$_SESSION['abc'];

But I get always an error like this:

Notice: Undefined index: abc

Any ideas to solve my problem? :/

firstly You have to set some value to this session attribute. — unknownbits
– unknownbits, Commented Oct 5, 2014 at 9:59
Are you trying to create a session variable or are you expecting it to have been created already? — bcmcfc
– bcmcfc, Commented Oct 5, 2014 at 9:59
I expecting it to have been created already. I get the right value if I use $_SESSION['abc'] but $_SESSION[$string] doesn't work for me. — Bene
– Bene, Commented Oct 5, 2014 at 10:01

Yang · Accepted Answer · 2014-10-05 10:01:09Z

1

Simply calling

$string = 'abc';    
$_SESSION[$string];

is not enough. It's only becomes available when you assign some value to it.

$string = 'abc';    
$_SESSION[$string] = 'test';

echo $_SESSION['abc']; //test

Also, make sure that session_start() is called on a page you're accessing it.

answered Oct 5, 2014 at 10:01

Yang

8,7408 gold badges35 silver badges61 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

yeah echo $_SESSION['abc'] works fine but not echo $session[$string]

$session is not predefined superglobal variable. if you simply want to make it work, then assign a reference like $session =&$_SESSION above