You’ve covered the core of Go. This last section introduces three features that aren’t used in every program but are essential for any Go developer to understand:

What’s in this section

1. Testing — Go’s built-in testing tools and the testing package
2. Reflection — looking at types and values at runtime
3. Generics — writing functions and types that work with many types, added in Go 1.18

Reflection and generics are both powerful and easy to misuse. The lessons here teach you what they are, when to reach for them, and (just as important) when not to.