Writing a modular program

Question

I want to make my program "modular" and I'm wondering if I'm taking the right approach to this.

What I mean by this is I want to have some reusable "processing" stuff contained within it's own c# files. In this way, I could simply copy the files between projects to be able to reuse my code. Since this probably doesn't make sense, let me explain with an example.

Program.cs

static class Program
{
    static void Main()
    {
        int[] x = {0, 0, 0, 0, 0};
        BClass b = new BClass(x);
        Console.Write("[ ");
        foreach (int i in x)
        {
            Console.Write(i + " ");
        }
        Console.Write("]\n");
        Console.Read();
    }
}

BClass.cs

class BClass
{
    int[] x;
    public BClass(int[] x)
    {
        for (int i = 1; i < 5; i++)
        {
            x[i] = i;
        }
    }
}

Now, this works fine, I get the output I would expect, but it feels wrong, I guess? In addition to my gut feeling, I am getting warnings (as I would expect) because the BClass object is unused. Ultimately, my question is What is the best way to make a program modular like this? Using a class feels wrong because I end up with a reference to an object that will never be used. Perhaps I'm using the class wrong?

Answer 1

It looks like you want to have some logic that you can run from anywhere in your application. For that, you'd use a static method.

A Static method requires no instance to run.

Since all BClass does is contain a static method, you might as well make BClass static too. A static class is a class that cannot be instantiated. It only exists to contain static methods.

public static class BClass
{
    public static void DoStuff(int[] x)
    {
        for (int i = 1; i < 5; i++)
        {
            x[i] = i;
        }
    }
}

And when you want to use this logic, you simply do this

BClass.DoStuff(myArray);