Although the book was first published in 2004, its contents remain relevant in 2021. PHP has evolved significantly over the years, and the book has been updated to cover the latest versions of the language, including PHP 7 and PHP 8.
For modern development (PHP 8.x), you may want to supplement this book with updated documentation, as PHP 5.2 is significantly outdated and many of its features have changed or been deprecated. Although the book was first published in 2004,
Instead of chasing a 15-year-old PDF, consider these : consider these :