Although the book was first published in 2004, its contents remain relevant in the current programming landscape. PHP 7 and later versions have introduced several changes, but the core concepts and syntax remain the same. The book provides a solid foundation in PHP programming, making it an excellent resource for developers who want to learn the language.
Using Holzner’s code directly in a PHP 8 environment will trigger deprecation warnings or fatal errors. You would spend more time updating examples than learning.
These are more up-to-date than any 2008 PDF.