Composition over Inheritance

Go deleted inheritance on purpose

The closing lesson, and the one that reframes all the others. Go has no classes and no inheritance — no extends, no base class, no super. That sounds like a missing feature; it's a deliberate design choice. Half the Gang-of-Four catalog exists to work around the rigidity of inheritance hierarchies. Remove inheritance and many of those patterns simply evaporate.

Go replaces inheritance with two tools: struct embedding (composition) and small interfaces. You've used both all course. This lesson names them.