Always Use Interfaces

How to follow the principle of Couple To Abstractions, Not Concretions, and how to avoid tempting others to break the rule. 🎓 Get the book: https://geni.us/hNDE 💚 BUY MY BOOK: https://theobjectorientedway.com Watch before:    • The Only Time You Should Use Polymorphism   Watch next:    • Depend on Abstractions not Concretions (Fr...   FURTHER RECOMMENDED READING: https://geni.us/zzlx (Dependency Injection: Principles, Practices, and Patterns) https://geni.us/IBhtLnh (Clean Architecture) https://geni.us/k8KhT3 (Refactoring) https://geni.us/nlbA6 (Head First: Design Patterns) 00:00 Intro 00:26 The rule 01:10 Problem 1 02:29 Problem 2 03:44 Solution 05:33 Motivation 07:05 Summary