Refactor class.Product.php and class.S.php for improved code readability and maintainability

autoload/shop/class.Product.php

@@ -795,7 +795,7 @@ class Product implements \ArrayAccess
   {
     $result = array();
 
-    while ( list($key, $values) = each( $input ) )
+    foreach ( $input as $key => $values )
     {
       if ( empty( $values ) )
         continue;
@@ -834,7 +834,7 @@ class Product implements \ArrayAccess
 
   public function __get( $variable )
   {
-    if ( array_key_exists( $variable, $this -> data ) )
+    if ( is_array( $this -> data ) and array_key_exists( $variable, $this -> data ) )
       return $this -> $variable;
   }