Question

I don’t understand why this code won’t only delete the pizza_id with the given key that is passed through the URL. I echo back the $_GET['key'] value to check if I have the desired number and it works fine.
The key value comes from another foreach $key=>$value loop that builds the shopping cart and has a delete link with the pizza id and the $key in it.

switch ($action) {
    case 'add':
        if ($cart) {
            $cart .= ','.$_GET['pizza_id'];
        } else {
            $cart = $_GET['pizza_id'];
        }
        break;
    case 'delete':
        echo "KEY: ".$_GET['key']."<br>";
        if ($cart) {
            $items = explode(',',$cart);
            $newcart = '';
            foreach ($items as $key => $item) 
            {
                if ($_GET['pizza_id'] != $item && $GET['key']!= $key ) 
                {
                    if ($newcart != '') 
                    {
                        $newcart .= ','.$item;
                    } 
                    else 
                    {
                        $newcart = $item;
                    }
                }
            }
            $cart = $newcart;
        }
        break;
}

EDIT: maybe I should also mention the basis of the code comes from this webpage http://v3.thewatchmakerproject.com/journal/276/

Answer 1

Well, at a minimum, you don’t need the $key in the foreach.

if ($cart) {
    // you car is now an array of $items.
    $items = explode(',',$cart);
    $key = $_GET[ 'key' ];
    // are you sure pizza_id is correct too? You may want to echo/log it
    // if there is an $item which corresponds to $key, remove it.
    if( isset( $items[ $key ] ) )
          unset( $items[ $key ] );

    // this loop searches for all indexes of $_GET[ 'pizza_id' ] and removes them
    // comment this out if you don't want to do that. For some reason 
    // I missed it the first go round.
    while( ($pos = $array_search( $items, $_GET[ 'pizza_id' ] ) !== FALSE )
    {
        array_splice( $items, $pos, 1 );
    }
    // implode afterwards
    $cart = implode( ',', $items );
}

Another poster pointed out that your original code also has $GET['key']. Badness 10000. Do you have your warnings and error output set at the maximum level during development?