CSharp-Coder

Learn C# interfaces vs abstract classes with real code examples. Master when to use each, best practices, and common pitfalls. Start coding smarter today. If you have ever sat in a technical interview or stared at a design decision in Visual Studio, you have hit this question: C# interface vs abstract class — which one should you use? It is one of the most searched C# topics for a reason. Both let you define contracts and share behavior, both power polymorphism, and both look deceptively similar at first glance. But choosing the wrong one leads to rigid, hard-to-maintain code. In this complete guide, we will break down the real difference between interfaces and abstract classes in C#, show runnable code examples, cover modern C# features like default interface methods, and give you a clear decision framework. Whether you are a beginner learning C# OOP concepts or a senior engineer refining your architecture, this article will make the choice obvious. What Is an Interface in ...