How to achieve same override experience in C# as in Java?

Question

Considering the following Java code:

public class overriding {
    public static void main(String[] args) {
        b b = new b();
        a a = (a)b;
        a.Info();
        b.Info();
    }
}

class a {
    void Info() {
        System.out.println("I'm a");
    }
}

class b extends a {
    void Info() {
        System.out.println("I'm b");
    }
}

And now let's try to do the same in C#

namespace ConsoleApplication2
{
    class Program
    {
        static void Main(string[] args)
        {
            b b = new b();
            a a = (a)b;
            a.Info();
            b.Info();
            Console.ReadLine();
        }
    }

    class a
    {
        public void Info()
        {
            Console.WriteLine("I'm a");
        }
    }

    class b : a
    {
        public void Info()
        {
            Console.WriteLine("I'm b");
        }
    }
}

The Java example output

I'm b

I'm b

The C# version output

I'm a

I'm b

Is there a way to implement class b so that it prints "I'm b" twice? Please notice i'm not looking at a way to change a.

Answer 1

In Java, methods are virtual by default. In C# they are not, and you need to use the keywords "virtual" and "override" for the method declarations in classes a and b, respectively.

Answer 2

In C# version, you need to use override keyword in the class b method, and also you need to make the method in class a virtual explicitly. In Java, methods are virtual by default. That's not the case in C#. You need to tell that explicitly:

class a
{
    public virtual void Info()
    {
        Console.WriteLine("I'm a");
    }
}

class b : a
{
    public override void Info()
    {
        Console.WriteLine("I'm b");
    }
}