using System;

interface I

{

​

}

​

public class A : I

{

​

}

​

public class B:A

{

​

}

​

public class C : B

{

​

}

​

public class D

{

​

}

public class Program

{

    public static void Main()

    {   

        ISImpl isImplObj = new ISImpl();

        // baseref is Base and various other scenarios involving inheritance

        A afirstObj = new B();

        A aSecondObj = new C();

        Console.WriteLine(isImplObj.Is(afirstObj, typeof(B)));

        Console.WriteLine(isImplObj.Is(aSecondObj, typeof(B)));

        Console.WriteLine(isImplObj.Is(aSecondObj, typeof(C)));

        Console.WriteLine(isImplObj.Is(new A(), typeof(C)));

        Console.WriteLine();

        // 6 is int || 6 is long || 6 is 6 and various other scenarios

        int integr = 6;

        Console.WriteLine(isImplObj.Is(integr, typeof(long)));

        Console.WriteLine(isImplObj.Is(integr, typeof(int)));

        Console.WriteLine(isImplObj.Is(6, 6));

        Console.WriteLine();

        // same with float types

        float floatv = 12.22f;

        Console.WriteLine(isImplObj.Is(floatv, typeof(float)));

        Console.WriteLine(isImplObj.Is(integr, typeof(double)));

        Console.WriteLine();

        // obj is Interface and various other scenarios with interface

        I ii = new C();

        Console.WriteLine(isImplObj.Is(ii, typeof(I)));

        Console.WriteLine(isImplObj.Is(ii, typeof(C)));

        Console.WriteLine(isImplObj.Is(ii, typeof(B)));

        Console.WriteLine(isImplObj.Is(new D(), typeof(I)));

        Console.WriteLine();

        // null is Type

        Console.WriteLine(isImplObj.Is(null, typeof(C)));

        // AS implementation

    }

}

public class ISImpl

{

    public bool Is(Object obj, Type typeInIs)

    {          

        if(obj != null)

        {

            return obj.GetType().Equals(typeInIs) || obj.GetType().IsSubclassOf(typeInIs) || (obj.GetType().GetInterface(typeInIs.ToString()) != null);

        }

        else

        {

            return false;

        }

    }

    public bool Is(Object firstObj, Object secondObj)

    {          

        return firstObj.Equals(secondObj);

    }

}