A New Dev’s Guide to Structuring Object-Oriented Programming Projects

When just starting out, I’ve had multiple students ask me how to ‘start’ a side project–but by ‘start’, they really mean ‘how do I organize my files’?  Although modern IDEs and programming languages scaffold quite a bit of structure for new projects, it can be daunting to stare down the editor for the first time.  Here are some tips to help you effectively plan out the architecture and file structure for an object-oriented programming project:

Make a Plan

What are the requirements of your project?  Write down the main features of the project, and then break those main features into smaller components.  Try to identify similar pieces of functionality, or functionality that deals with specific tasks (such as getting data from a database, or displaying information to the user), and group features into categories according to their functionality.

Once you have a clear understanding of the project requirements, start brainstorming what classes and objects will be needed to implement them, and write them down.  If you’re a visual thinker, you can create a class diagram to help you visualize the relationships between different classes.  Think about the potential relationships between your classes, and note any hierarchies or interfaces that will need to be implemented.

Organize your Code

Create a folder/directory structure that makes sense to you.  One way to organize code is to put all of your classes into one folder, and have a separate folder for interfaces.  Another way is to group classes and interfaces into folders based on their functionality.  (You can even combine these two approaches, although you may end up with a lot of folders!)

If you are following an architectural design pattern, such as MVC or the DAO pattern, make sure you create a file structure that follows the design pattern. 

Be Consistent

Decide on a naming convention for your classes, methods/functions, and variables–and then make sure to follow it.  Sometimes, there will be existing naming conventions for the language you are programming in–if so, follow that.  Being consistent with your naming will help to make your code more readable and understandable to other developers (remember, ‘other developers’ also includes you in the future).  

Similarly, decide on a file structure and make sure the correct files are in the correct directories.  If you decide to have a subdirectory for interfaces in a particular class directory, make sure that only interface files are in the subdirectory. If you’re implementing a design pattern, make sure to follow it across your entire project.

Accept Change

Regularly review and refactor your code.  Remember, it’s your project, so you call the shots!  If a particular way of organizing code isn’t working for you, you’re allowed to change it up–move files around, rename things, and rewrite pieces of your application so that they make sense.  If something isn’t working out the first way you tried writing it, go back to the drawing board and try again from the beginning.  The plan you wrote in step one is very likely not going to be the final architecture of your application; it was just an exercise to help get you started on your project. 

By following these tips, you can effectively plan out the architecture and file structure for your object-oriented programming project. Remember to stay organized and flexible, and be willing to adjust your plan as you go along.  Happy coding!