Now we know how to define a class and create an instance of it, we need to see how we can extend the methods capabilities. We're going to use a syntax like the following example:

using System;

​

public class Person

{

    public string GetFullName()

    {

        return "John Smith";

    }

}

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

In the above example, we've extended our Person class with some additional functionality. In this instance, we've added a method called GetName which allows us to return a string variable. You've met methods before:

public class Program

{

    public static void Main()

    {

​

    }

}

The  Main  method of your program is like our  GetName  method, they both belong to a class ( Program  or  Person ), the big difference between them, is the  Main  method returns  void  and our  GetName  method returns a  string .  void  is a special keyword which essentially means 'nothing'. Let's see how we can declare a method.

Starting with our blank  Person  class:

public class Person

{

​

}

We need to add some code within the  {  and  }  braces. Let's add the following and see what it means:

public string GetFullName()

{

​

}

In our method declaration, we're telling the compiler that we want a method named  GetFullName , which returns  string . The parenthesis characters  (  and  )  would allow us to provide arguments, but we're not going to do that right now. Again, we also use the  public  keyword to tell the compiler that this will be a method that can be externally called. We also require some additional braces  {  and  }  to mark the boundary of the method body.

Putting that together, we get the following:

public class Person

{

    public string GetFullName()

    {

​

    }

}

But this won't compile yet! The reason being is that in our declaration of our method, we've stated that it should return a  string  value, but we haven't provided one. Let's fix that by adding the following line within the  GetFullName  method:

return "John Smith";

If the method should not return anything, then you can use the return type void. void is a special keyword in C# that basically says "I don't return anything". Here is an example of a void method:

public void WriteName()

{

    Console.WriteLine("John Smith");

}

You've previously met the void keyword in our Program class:

public class Program

{

    public static void Main()

    {

​

    }

}

So with that now added we can compile our code.