Question

When I first started programming, I wrote everything in main. But as I learned, I tried to do as little as possible in my main() methods.

But where do you decide to give the other Class/Method the responsibility to take over the program from main()? How do you do it?

I’ve seen many ways of doing it, like this:

class Main {   public static void main(String[] args)   {     new Main();   } } 

and some like:

class Main {     public static void main(String[] args) {      GetOpt.parse(args);      // Decide what to do based on the arguments passed     Database.initialize();     MyAwesomeLogicManager.initialize();     // And main waits for all others to end or shutdown signal to kill all threads.   } } 

What should and should not be done in main()? Or are there no silver bullets?

Thanks for the time!

Answer 1

In my opinion, the ‘main’ of a sizable project should contain around 3 function calls:

• Calling an Initialization function that sets up all the required settings, preferences, etc. for the application.
• Starting up the main ‘controller’ of the application
• Waiting for the main controller to terminate, and then calling a Termination function that cleans up anything that needs to be cleaned up in ‘main’ (though the controller will have taken care of most of the cleanup already).

Any sizable application will be divided into chunks of functionality, usually with some hierarchy. The main controller may have several child controllers for specific features.

Doing it this way makes it much easier to locate specific functionality, and separation-of-concerns is better.

Of course, as other replies have said, there really is no silver bullet in software development. For a short project I might put everything in main just to get things up-and-running quickly. I think also depends on the language – some options may be easier than others in particular languages.