Chapter 10. Maintaining Sessions with PHP

The true art of memory is the art of attention.

”Samuel Johnson

This chapter is all about maintaining state ”the process of preserving variable values across script invocations. First, we discuss PHP 4's new session management features, and then round out the section with a small, to the point, shopping cart system. Then we investigate PHP's serialization functions (WDDX included), which are efficient ways to store PHP variables .