Call to a member function on a non-object, not enough to add

Call to a member function on a non-object, emergency online, etc., not enough to add
CALSS Cart {

function get_item ()
{
if (!empty ($_session[' cart ')) &&is_array ($_session[' cart '))
{
return $_session[' cart '];
}
Else
{
$_session[' cart ']=array ();
return $_session[' cart '];
}
}

}

$data = $cart-get_item ();

PHP version 4.3.11,php version 4.4.4 test error, call to a member function on a non-object

PHP version 4.4.6, PHP version 5.1.2 Test Normal, you can print out the Print_r ($data);

------Solution--------------------
You'd better be a new instance.
------Solution--------------------
It's weird to be normal.


Class Cart {

function get_item ()
{
if (!empty ($_session[' cart ')) &&is_array ($_session[' cart '))
{
return $_session[' cart '];
}
Else
{
$_session[' cart ']=array ();
return $_session[' cart '];
}
}

}

$cart = new cart ();
$data = $cart-get_item ();
------Solution--------------------
Call to a member function on a non-object
===========================================
Call a member function for an empty object.
"Non-object", stating that the object is not instantiated, that is, there is no new.
------Solution--------------------
Well, liyong98847 () makes sense. You check if the register_globals in PHP.ini under PhP4 is off, and if it is on, $_session[' cart ' is equivalent to $cart.

In the case of Register_globals=on:
==============================================
$cart = new Cart ()//change the value of $_session[' cart ' in the cart class, and change the value of $cart
$data = $cart-get_item ();//$cart has been altered, resulting in a member function on a non-object

You can change the name of the variable to try, if there is no error, proof is the above-mentioned problem
====================================================
$c = new cart ();
$data = $c-get_item ();

------Solution--------------------
Several of LS are very clear.

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