Question

I’m new to the programming world.

I have a data extractor program which extracts data from MySQL into a word template file. I don’t understand how the main program knows which argument to pass into the parameters. When running the exe, how does the program knows that "Haha, I need to pass a string in there, And it is precisely this string right here" ???.

EDIT:
This program is supposed to be run when pressing a `Extraction Button’ but how the exe program knows where is the string arg parameters? where does the exe get it from?

MAIN CODE

private static void Main(string[] args)
        {
            try
            {
                if (args[0] == "ALL" || args[0] == "*" || args[0] == "all")
                {
                    PrintARs();
                    Console.Read();
                }
                else
                {
                    CreateARDocument(args[0]);
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
                Console.Read();
            }
        }

Answer 1

There are a number of ways:

1. You don’t. You just let people guess until they get it right.
2. When invalid input, or no input, is provided the job could write out instructions to the console to help the user do it correctly
3. You could provide external documentation, i.e. a readme.txt file.
4. You could make the program interactive, rather than using command line arguments (write out text asking for what you want, and then get the input from standard input.
5. You could make a real GUI for the program, with a textbox and a button for input. Usually when you see programs such as this (using command line args) it’s because it’s just a tool that isn’t designed to really be user-friendly; it will be used by programmers who just know how to use it, or it will be used by other programs.