Static methods

In C#, all methods must be declared within classes or structs. Normally you will need an object upon which you will call any method.

This results in one challenge, how do you create methods like Main which can be accessed without an object? After all, Main needs to be called before we have the chance to create any objects.

To address this challenge, languages like C# allow you to declare static methods within a class that can be called on the class itself. This allows methods to be called without any object. Main needs to be static so that it can be used as the entry point for the program.

Static Methods Why, When, and How?

With the object-oriented programming style, you don’t often need to create static methods. They are occasionally useful for the situations where you want a general function or procedure that can be accessed anywhere without needing an object.

Here are some examples of static methods we have been using previously:

The Console class has static methods to interact with the terminal. This includes WriteLine and ReadLine.
The Convert class contains static methods to convert data between common data types.
The SplashKit class contains static methods to call its various functions.

In C

Examples

The following code declares three static methods. Notice that these are very similar to the functions and procedures you have been creating in C/C++.

class MyProgram
{
    public static void SayHelloTo(string name)
    {
        Console.WriteLine($"Hello {name}!");
    }

    public static string ReadString(string prompt)
    {
        Console.Write($"{prompt}: ");
        return Console.ReadLine();
    }

    public static void Main()
    {
        string name = ReadString("Name");
        SayHelloTo(name);
    }
}

As you read over the code you should be able to link the code with concepts you are already familiar with:

Variable declarations are the same as we saw in Part 1.
Parameters use a very similar format as we used in C/C++.
Methods can return data just like functions in C/C++.
Methods that do not return data are declared as void methods.
You can call other static methods within the same class without using the class name.