Array and strings issue

nyl

I have this code:

$_SESSION['productid'][] = $productid;

the first time I load the page it works fine, the second time it gives me this error:

Fatal error: [] operator not supported for strings in......

any solution to avoid this error ?

halojoy

Maybe you have something more in your page?
That single line can not cause a FATAL error all by itself
🙂
Well, what looks a bit strange to me is the trailing [ ] in SESSION variable.

$_SESSION['productid'][] = $productid;
// maybe should be:
$_SESSION['productid'] = $productid;

nyl

the script is a simple shopping cart.

I keep adding new items to the cart (add.php) using this code:

$_SESSION['productid'][] = $productid; 
$_SESSION['prod_name'][] = $prod_name;

and then I list the items in the cart (showcart.php) using this code:

$_SESSION['array_len'] = count ($_SESSION['productid']); 

for ($i = 0; $i < $_SESSION['array_len']; $i++) { 
     echo"Prod. ID: " . $_SESSION['productid'][$i]; 
     echo"Prod. Name: " . $_SESSION['prod_name'][$i]; 
}

etc...

it works fine on my local machine all the time.
it works fine on the server the first time i load the page containing this script (add.php) . after that it gives the fatal string error.

nyl

$_SESSION['productid'][] is a multidimensional array. It means you can have:

$SESSION['productid'][0] = "132";
$SESSION['productid'][1] = "133";

$SESSION['prod_name'][0] = "T-shirt";
$SESSION['prod_name'][1] = "Bike";

and so on.

since the cart is composed usually by more then a product and they all share the same fields, a multidimensional array is the way to go.

halojoy

okay.
So if you have 4 products in $_SESSION['productid'], product index [0] [1] [2] [3]

What happens when you try:
$_SESSION['productid'][] = $productid;

Is this product added as $_SESSION['productid'][4] ???

nyl

okay.
So if you have 4 products in $_SESSION['productid'], product index [0] [1] [2] [3]

What happens when you try:
$_SESSION['productid'][] = $productid;

Is this product added as $_SESSION['productid'][4] ???

right. it is added on top of the last one, in the case above it is assigned the number 4 like you just mentioned.