One shopping solution of many is a session solution with classes (OOP).

Standard Features of PHP Basket Class with OOP:
- Cookie control,
- presentation of products,
- basket handling (add, remove, increase, reduce quantity, zero result handling, subtotal and total),
- session check plus detection of string manipulations.

The handling of the orders is done by the basket class.

That for we need two sessions: one for the basket with the orders and one for the quantities of orders (which are identified through arrays and the product id).

In the next step we control, if the user takes the same order more then once. Whith a control variable (+/-) and a foreach loop we increase or reduce the quantity.

The shopping basket is a combination between a while-list-each- and a database-query. If quantity result is zero, order will be removed from basket.

Security Feature of PHP Basket Class with OOP:
Intrudors will be recognized by a explode script that determines string manipulations (in this example a table name, but also very usefull for other strings).