OOD / OOP Etudes / Code exercises

Question

I\'ve been searching the web for some time now. I am looking for small sample exercises for OOD practice (& for some internal TDD workshops).
If there is one single plac

Answer 1

Questionnaire Practice Problem

A problem I've worked on in a couple of different jobs is that of writing some generic, data-driven survey/questionnaire functionality. It's not majorly complex, but has enough interesting avenues to be a good OOD practice problem I think. It's definitely real-world and crops up in a lot of places.

You can start off thinking about how to structure a Survey. It is obviously made up of Questions, but do you also want Categories? Can a Question have subquestions? Can a subquestion have subquestions? How deep can you go?

A question probably needs to have potential Scores. What types of scores can you have? What types of questions can you have (multiple choice, multiple answer, freetext, etc.)?

Once you've got the basic business logic, you can also think about how you display a survey . Maybe you have a SurveyRenderer and a QuestionRenderer? How do you decide how to render different types of questions? (Maybe you use a Strategy pattern... as in this SO question.) How do you render a read-only version of the survey?

You can also think about persistence. How do you record responses to a blank questionnaire? How does your object graph of a survey get mapped into a database (or some other backing store), and vice versa?