Last month I talked about how, despite PHP arrays being one of the nicest things about the language, there were times where real data structures could help. There were various ways to use arrays as more “traditional” data structures, as well as the options provided by the Standard PHP Library, or SPL. If you can install PHP extensions, there is an actual Data Structures extension which implements actual data structures at the C level. This lets you use traditional data structures that can work better than bare arrays or the SPL. This month we will dive deeper into the Data Structure extension.