Re: Object Undefinded index

I'm just adding a working example to my last post; check the implementation part at the end of the script; Cheers, Allex -------------------- <?php class Item {

    var $_productID;
    var $_quantity;

    function Item($productID, $quantity) {
      $this->_productID = $productID;
      $this->_quantity = $quantity;
    }

    function setProductID($productID) {
      $this->_productID = $productID;
    }

    function getProductID() {
      return $this->_productID;
    }

    function setQuantity($quantity) {
      $this->_productID = $quantity;
    }

    function getQuantity() {
      return $this->_quantity;
    }

} class Cart {

    var $_items;

    function Cart() {
      $this->_items = array();
    }

    function addItem($item) {
      $this->_items[] = $item;
    }

    function getItems() {
      return $this->_items;
    }

} // test implementation $MyCart = new Cart(); $MyCart->addItem(new Item("10", 20)); $MyCart->addItem(new Item("20", 45)); $MyCart->addItem(new Item("30", 55)); foreach ($MyCart->getItems() as $item) { echo "ProductId: " . $item->getProductID() . " Quantity: " . $item->getQuantity() . "<br>"; } ?> Steve Turner wrote:

I am just learning to use objects. I am messing around with a shopping cart object, but am having confusing problems. I am getting an undefined index error when trying to assign a key value pair to an array variable within an object. I am confused becuase I believe this is how you assign array variables outside an object. It acts like the variable is undefined. Thanks for the help. Steve Turner //-------------------------------------------------- class Cart {

    var $items;  // Items in shopping cart

    // Add $quantity articles of $product_id to the cart

    function add_item ($product_id, $quantity = 1)
    {
        $this->items[$product_id] += $quantity;
    }

    // Take $quantity articles of $product_id out of the cart

    function remove_item ($product_id, $quantity)
    {
        if ($this->items[$product_id] > $quantity)

{

            $this->items[$product_id] -= $quantity;
            return true;
        }

else {

            return false;
        }
    }

} //I am interacting with the object with the following code $cart = new Cart; $cart->add_item("10", 1); foreach ($cart as $product_id => $quantity) { echo $product_id . "<br>" . $quantity; }