Question

• The issue is the results from local host are not matching up with the live site when pushed by FTP. The
  below code seems make me believe the array is not be created
  properly on the server. In addition, it is doing some funky stuff, as seen below. The error is “Cannot use a scalar value as an array” on line 97, or $_SESSION[“count”][$i] +=1. Do you see the reason why? Or is there a different mistake I made?

• To summarize the code, the following session arrays make up the core of the shopping cart: $_SESSION[‘item_id’][$i], $_SESSION[‘size’][$i],
  $_SESSION[‘price’][$i], $_SESSION[‘count’][$i] … and they all correlate to one another. Therefore a check is done to see if the combination exists, if so it appends the count, if not, adds the item combination for the first time.

Local Host

In Stock: 3
Distinct Item Count: 3

Array ( [0] => 1 [1] => 2 [2] => 2 ) Item Array: 1
Array ( [0] => S [1] => M [2] => L ) Size Array: 1
Array ( [0] => 15 [1] => 20 [2] => 20 ) Price Array: 1
Array ( [0] => 15 [1] => 35 [2] => 17 ) Count Array: 1

Quantity Increased to 18 

1 
S 
15
15


2 
M 
20
35


2 
L 
20 
18 

|3 ($1285) 

Live Site – First Add

In Stock: 5
0


1
M
20
1

|1 ($20)

Live Site – Second Add

In Stock: 5
Distinct Item Count: 1

1Item Array: 1
MSize Array: 1
300Price Array: 1
1Count Array: 1


Warning: Cannot use a scalar value as an array in /public_html/shop/helper/addtocart.php on line 97
Quantity Increased To

1
M
2


|1 ($0)  

Code

    if (isset($_SESSION["item_id"]) && is_array($_SESSION["item_id"])){
        echo "Distinct Item Count: " . count($_SESSION["item_id"]);
        echo "<br/>";
        echo "<br/>";
        echo "Item Array: ";
        print_r($_SESSION["item_id"]);
        echo "<br/>";
        echo "Size Array: ";
        print_r($_SESSION["size"]);
        echo "<br/>";
        echo "Price Array: ";
        print_r($_SESSION["price"]);
        echo "<br/>";
        echo "Count Array: ";
        print_r($_SESSION["count"]);
        echo "<br/>";
        echo "<br/>";
    }

    //check for current product combination in visitor's shopping cart content

    //find count in cart
    if (!isset($_SESSION["item_id"])){
      $count = 0;
      }else{
        $count = count($_SESSION["item_id"]);
      }
    echo $count;
    echo "<br/>";

    if ($count == 0){

        //declare arrays
        $_SESSION["item_id"] = array();
        $_SESSION["size"] = array();
        $_SESSION["price"] = array();
        $_SESSION["count"] = array();
        $_SESSION["total"] = array();

        //add first item to cart
        $_SESSION["item_id"][] = $item_id;
        $_SESSION["size"][] = $size;
        $_SESSION["price"][] = $price;
          //fundraiser and corporate
          if (($_SESSION["acctype"] == 2 || $_SESSION["acctype"] == 3) && isset($_SESSION['userid'])){
              //update count, add 100
              $_SESSION["count"][] = 100;
              }
          else{
              $_SESSION["count"][] = 1;
          }
    }else{
        $flag=0;
        $i=0;
        while ($i <= $count){
           if( ($_SESSION["item_id"][$i] == $item_id) && ($_SESSION["size"][$i] == $size) ){
           //fundraiser and corporate
              if(!isset($_SESSION["acctype"]) || $_SESSION["acctype"] == 1){
                 //update by one
                  $_SESSION["count"][$i] +=1;
                }
              elseif(isset($_SESSION['userid']) && ($_SESSION["acctype"] == 2 || $_SESSION["acctype"] == 3)){
                    //update count, add 100
                    $_SESSION["count"][$i] +=100;
                }
              else{
                  echo "Hmm";
                }
              //update cart stats
              echo notify('Quantity Increased To' . ' ' . $_SESSION["count"][$i]);
              //was there combination match?
              $flag = 1;
              }
        $i++;
        }
        if($flag == 0){
                  $_SESSION["item_id"][] = $item_id;
                  $_SESSION["size"][] = $size;
                  $_SESSION["price"][] = $price;
                    //fundraiser and corporate
                    if (($_SESSION["acctype"] == 2 || $_SESSION["acctype"] == 3) && isset($_SESSION['userid'])){
                        //update count, add 100
                        $_SESSION["count"][] = 100;
                    }else{
                    $_SESSION["count"][] = 1;
                    }
         }
    }

Answer 1

Short answer: Check to see if register_globals is enabled on your live server using var_dump(ini_get('register_globals')) or phpinfo() . If register_globals is enabled, the preferable solution is to disable register globals—it leads to security problems and as of PHP 5.3 is deprecated.

Longer answer: ‘Cannot use a scalar value as an array’ means that a scalar value (e.g. number) exists in the variable that you are referencing as an array. I do not see anywhere that you assign a scalar directly to $_SESSION["count"].

However, if register_globals is enabled $count would become a reference to $_SESSION["count"], which means $count = 0 would be setting $_SESSION["count"] to a scalar. Again, the preferable solution would be to disable register_globals, but a workaround would be to rename the $count variable to something else.