Question

I have some doubt to implementation of class and interface

I have 2 class like this

Public Class A:IFinal
  {
      private string name=string.Empty;

        A()
        {
            name = "Pankaj";
        }

        public string MyName()
        {
            return name;
        }

        public string YourName()
        {
            return "Amit";
        }
   }

Public  Class B:IFinal
 {
     private string name=string.Empty;

        B()
        {
            name = "Amit";
        }

        public string GetNane()
        {
            return name;
        }

        public string YourName()
        {
            return "Joy";
        }
   }

Question:

1. Now i have a interface IFinal and i want to implement this interface in class A & B for method YourName() like this

   public interface IFinal
   {

        string YourName();// Class A & Class B
   
   
   }
   

Is it possible to implement on this way? if yes then How can i declare YourName() in interface and how can i use this?

2. Is it possible to declare virtual method in interface?like in class A & B we have a virtual method which need to be declare in interface.

Answer 1

You can make the method virtual in your implementation eg:

interface IFinal
{
    string YourName();
}

class A: IFinal
{
    public virtual string YourName() { return "Amit"; }
}

class B: IFinal
{
    public virtual string YourName() { return "Joy"; }
}

Or you could use a common base implementation which both A and B derive from, eg

interface IFinal
{
    string YourName();
}

abstract class FinalBase : IFinal
{
    public virtual string YourName() { return string.Empty; }
}

class A : FinalBase
{
    public override string YourName()
    {
        return "A";
    }
}

class B : FinalBase
{
    public override string YourName()
    {
        return "B";
    }
}

class C : A
{
    public override string YourName()
    {
        return "C";
    }
}

new A().YourName(); // A
new B().YourName(); // B

IFinal b = new B();
b.YourName(); // B

FinalBase b = new C();
b.YourName(); // C