setting one var to NULL empties another

sneakyimp

ok, can someone explain to me why emptying one session var empties a separate one??

here's the code

echo "\ncart going into session\n";
print_r($ec_cart);

  // serialize is necessary to make a copy of the cart
  $_SESSION['purchase_cart'] = serialize($ec_cart);

echo "\ncontents of purchase_cart\n";
print_r($_SESSION['purchase_cart']);

  $_SESSION['purchase_total'] = $cart_total;

  // empty old car vars
  $_SESSION['ec_cart'] = NULL;
  $_SESSION['cart'] = NULL;

echo "\nsession cart after nullified session\n";
print_r($_SESSION['purchase_cart']);
die("die time");

Here's the output:

cart going into session
Array
(
    [new_7_44c6c40a2b9eb] => Array
        (
            [type] => new
            [pkg_opt_id] => 7
            [extra_time] => 5
            [pkg_type] => gold
            [pkg_name] => Gold
            [max_pictures] => 3
            [price] => 1.99
            [additional] => 1.99
            [name] => Adfotos Gold, 3 photos
        )

)

contents of purchase_cart
a:1:{s:19:"new_7_44c6c40a2b9eb";a:9:{s:4:"type";s:3:"new";s:10:"pkg_opt_id";s:1:"7";s:10:"extra_time";s:1:"5";s:8:"pkg_type";s:4:"gold";s:8:"pkg_name";s:4:"Gold";s:12:"max_pictures";s:1:"3";s:5:"price";s:4:"1.99";s:10:"additional";s:4:"1.99";s:4:"name";s:22:"Adfotos Gold, 3 photos";}}
session cart after nullified session
die time

I vaguely recall something about array contents being passed by reference, but a serialized array? I don't understand 🙁

bogu

why dont u use unset, if one way is not working try the other way ..

sneakyimp

It seems to be working--both ways! ack!

I must have had a typo somewhere. it was driving me bonkers.

What is the difference between unset() and setting to null? unset would appear to eliminate every trace of the var. on the other hand, when unset is called in a subroutine, behavior differs.

Weedpacket

Um, you do realise it's not necessary to serialise an array before putting it in a session...? Okay; just checking.

I've never been inflicted by it by I understand that there have been some versions of PHP that got confused when you use both $foo and $SESSION['foo'] (or in your case $ec_cart and $SESSION['ec_cart']) whether they were supposed to be the same thing or not. But to be honest on a third re-reading I don't see how that would be relevant here ... To clutch at a couple of straws, what does the rest of $_SESSION contain - before and after?

sneakyimp

I used the serialize command hoping to disconnect any references that might somehow connect the various variables.

But...it seems to be working now. $_SESSION['purchase_cart'] is remaining defined as i wished (without serialization). I'm not sure what I changed but it's working. That's what i get for working so late i guess.