Introduction

In this chapter, we will show you how traits and interfaces work together. Then, we turn our attention to the design of a fallback mechanism that will catch errors and exceptions in situations where you were not able (or forgot) to define specific try/catch blocks. We will then venture into the world of unit testing, showing you first how to write simple tests, and then how to group those tests together into test suites. Next, we define a class that lets you create any amount of generic test data. We close the chapter with a discussion of how to easily manage sessions using new PHP 7 features.