As we have seen, with version 5, PHP has dramatically enhanced its object support. We have now covered most of PHP's object-oriented features. If you are excited by the prospect of working with objects and PHP, realize that this chapter is not even the end of the beginning. Object-oriented design is a vast subject but very rewarding. It is likely that PHP 5 will encourage a small revolution in design books for PHP, so keep your eyes on the bookshop shelves.
In this hour, you learned about class constants and explored a trick for using constant flags to store status settings. You learned how to use static properties and methods to control access to an object. You used the __call(), __get(), and __set() methods to overload object calls and the __destruct() method to handle the end of an object's life. You learned how to define, throw, and catch exceptions. Finally, you defined type functionality using abstract classes and interfaces.