Summary

One of the most important concepts you learned in this chapter is a general trend away from resources and toward objects. You learned where this trend is noticeable in the various PHP extensions covered in this chapter, and how to develop workarounds to avoid problems in code that relies upon resources. You also learned how to detect and develop code to address changes in XML extensions, especially in the SimpleXML and XMLWriter extensions.

Another important extension with significant changes covered in this chapter is the mbstring extension. You learned to detect code that relies upon changed mbstring functionality. As you learned, changes to the mbstring extension for the most part mirror changes made to the equivalent core PHP string functions.

You also learned about major changes to the GD, Reflection, and ZIP extensions. In this chapter, you also learned about changes to a number of database extensions, as well as a medley of additional extension changes to note...