Unreachable code detected C# (absolute beginner) [closed]

Question

Could you explain how should I avoid this warning: "Unreachable code detected" in Visual Studio 2010 Express ? I'm learning C# from a manual. It's an exercise for creating a simple method. I'm entering the example precisely as written in the book. Thanks.

public class Multiply 
{
    //Multiplies argument by 4 

    public static int MultiplyBy4(int aNumber)
    {
        return 4 * aNumber;
        //Shows ways of passing various arguments to a method public static void Main
        int x = 7;
        int y = 20;
        int z = -3;
        int result = 0;

        result = MultiplyBy4(x);
        Console.WriteLine("Passsing a variable, x : {0}", result);

        result = MultiplyBy4(y + 2);
        Console.WriteLine("Passing an expression, Y + 2: {0}", result);

        result = 5 + MultiplyBy4(z);
        Console.WriteLine("Using MultiplyBy4 in an expression: {0}", result);
        Console.ReadLine();
    }
 }

I don't understand the manual commentary: "Shows ways of passing various arguments to a method public static void Main" after creating the method with a parameter and a return value. How do I make the method MultiplyBy4 recognize x, y, z as being "aNumber" ? Maybe this is a retarded questions but I'm stuck here. Thanks.

Answer 1

The comment line is messed up and contains the definition of the Main method. The code should read:

    public class Multiply 
{
        //Multiplies argument by 4 
        public static int MultiplyBy4(int aNumber)
        {
            return 4 * aNumber;
        }

        //Shows ways of passing various arguments to a method
        public static void Main(string[] args)
        {
                int x = 7;
                int y = 20;
                int z = -3;
                int result = 0;

                result = MultiplyBy4(x);
                Console.WriteLine("Passsing a variable, x : {0}", result);

                result = MultiplyBy4(y + 2);
                Console.WriteLine("Passing an expression, Y + 2: {0}", result);

                result = 5 + MultiplyBy4(z);
                Console.WriteLine("Using MultiplyBy4 in an expression: {0}", result);
                Console.ReadLine();
            }
 }

Answer 2

The return statement is exiting the function here.

So the declarations of x,y,z and result, and the Console.Write will never run...