Multiple inheritance in C#

One of my interview questions I dare to ask is “Can you do multiple inheritance in C#?”.

So far, the correct answer always was ‘No’, but with the release of C# 8 the answer became more nuanced. Although a C# class can implement multiple interfaces it can inherit from only one base class.  Until C# 8, only the base class could provide code that is usable by the derived class.

With C# 8, interfaces can also provide code to their implementing classes. This allows us to share code without a common base class. Finally we can do a (kind of) multiple inheritance…

	interface ILogger
	{
	void Log(LogLevel level, string message) => Console.WriteLine(message);
	void Log(Exception ex) => Log(LogLevel.Error, ex.ToString());
	}

view raw ILogger.cs hosted with ❤ by GitHub