Here is a my code inside a c# project that targets .NET Core 3.0 (so I should be in C# 8.0) with Visual Studio 2019 (16.3.9) public interface IJsonAble { public string ToJson() => System.Text....

Can somebody explain how same function on same class behaved different? using System; public class HelloWorld { public static void Main(string[] args) { MyUpperScript mAsdfScript = new MyUpperS...

I have a .Net 6.0 application in Visual Studio 2019. I'm trying to get default interface implementations working. For some reason, it doesn't seem to be recognizing the default implementations in t...

I have this Simple Console program in .NET Core 3.1 with C# 8: using System; namespace ConsoleApp34 { public interface ITest { public void test() { Console.WriteLine("Bye World!");...

The following interface has no errors in a .NET Core Console application with C# 8.0 interface I { public abstract void f(); public virtual void g() => Console.WriteLine("g"); publi...

I really loved the idea of default implementations on interfaces in C#8. But after trying it the disappointment was big... So here's a simple example which I've found a part of the answer to in C#8...

C# 8 supports default method implementations in interfaces. My idea was to inject a logging method into classes like this: public interface ILoggable { void Log(string message) => DoSomethingW...

If I have a default interface method like this: public interface IGreeter { void SayHello(string name) => System.Console.WriteLine($"Hello {name}!"); } Can I have my concrete implementation ...

Consider the contravariant interface definition with a delegate: public interface IInterface<in TInput> { delegate int Foo(int x); void Bar(TInput input); void Baz(TInput input, Foo fo...

Consider the following code: interface I { string M1() => "I.M1"; string M2() => "I.M2"; } abstract class A : I {} class C : A { public string M1() => "C.M1&q...

In C# 8 and later, we have default interface methods, so: Doesn't it ruin the principle of interface? When should we use default interface methods instead of base (abstract) class?

Why is the behavior of Default Interface Methods changed in C# 8? In the past the following code (When the Default interface methods was demo not released): interface IDefaultInterfaceMethod { //...

Consider the code: class ChildClass : BaseClass { public void Method1() {} //some other method } abstract class BaseClass : IChildInterface { public virtual //<- If we add virtual so tha...

There is currently little documentation surrounding the limitations of events with the new C#8 default interface implementations (traits). I am particularly confused with the spec proposal. Not onl...

I know that an abstract class is a special kind of class that cannot be instantiated. An abstract class is only to be sub-classed (inherited from). In other words, it only allows other classes to i...

C# 8.0 has introduced a new language feature – default implementations of interface members. public interface IRobot { void Talk(string message) { Debug.WriteLine(message); } } The new...

Given that an auto property compiles to a get_method, a set_method and a private variable and since C# 8 is introducing default interface methods Can properties in Interfaces have default implement...

I know the feature doesn't exist in C#, but PHP recently added a feature called Traits which I thought was a bit silly at first until I started thinking about it. Say I have a base class called Cl...

According to https://blogs.msdn.microsoft.com/dotnet/2018/11/12/building-c-8-0/, one of the new features coming in C# 8 is the default implementation of interfaces. Will this new feature also impli...

Consider the following code example: public interface IPlayer { int Attack(int amount); } public interface IPowerPlayer: IPlayer { int IPlayer.Attack(int amount) { return amount + 50; } } p...

I heard that in Java 8 there is a flexibility of having function definitions in an Interface. I think we can have some default state with this feature in all the classes that are implementing such ...

I recently ran into a list of features that are being considered for addition in the next version of C#. One of them is called "default interface methods": https://github.com/dotnet/csharpla...