Reference counting is one of the hottest new features in PHP 4. It reduces the memory consumption of your PHP applications, improves performance, and provides you with some sophisticated programming tools. To get the most out of this new PHP 4 feature, it's important to understand exactly how it works and how it differs from PHP 3. Topics include: Data values in PHP 3, What is reference counting, Advantages of reference counting, Reference counting in PHP 4, Aliasing: added language flexibility in PHP 4, and How will reference counting effect you?.

Shows how to calculate an average of ratings example, given the accumulated total of all ratings and the total number of votes.

This demo shows how to use the regular expression support in PHP. These functions allow you to perform regular expression operations on strings. The regular expression language used is compatible with the extended regular expression syntax as specified in the egrep man page on most Unix systems.

Put some logic in your pages with PHP. Minimize the hassles for yourself and your users. This step-by-step tutorial shows examples of how PHP can be used for site navigation.