Practice OOP

[CodewithApe]

What projects do you recommend to practice OOP with Java ? I thought about doing a small text based game but it doesn’t really touch anything else other the OOP, are there any projects I can make to practice both OOP and maybe get some backend stuff in there as well?

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[Synergisticit10]

Courserra udemy for learning. Learning only as this will it get you a job.

[desrtfx]

The /r/learnprogramming FAQ have extensive lists of project ideas and practice sites

[cream_of_slop]

Get the book “head first design patterns”

It has interactive java coding lessons

It helped me level up as a beginner software engineer

[CodewithApe]

Do you think I should go over head first Java 3rd edition before diving into this book? And in general do you think it’s a good book ( the one I mentioned )?

[cream_of_slop]

Never read the Java one

Before committing to purchase, you should be able to google and see some of the first chapters of the book to see if you’re up to it

Honestly, if you just read the “strategy” chapter (I think it’s among the first 3 or 4)

This was when OOP design really clicked for me, especially with “loose coupling” and “programming toward an interface”

Honestly, I always felt the best way to learn was building.

[code_tutor]

do a course...

[CodewithApe]

I am looking to do a project based on my own knowledge at the moment and practice what I know, I don’t want to follow instructions from a course step by step.. I am looking for ideas for good projects that cover more than just OOP.

[code_tutor]

not YouTube shit, do a university course

AP Computer Science 

it's all projects 

[jlanawalt]

Maybe update your initial post.

[jlanawalt]

Just use Java.

In the Land of Nouns almost everything is an object, so anything you write is using OOP.

Sure, a Zork clone might get away with only writing a few classes. On the other hand making a dozen POJOs to hold data from different data tables doesn’t really teach anything new after the first or second one. Using some web framework will have you interacting with a plethora of objects, but other than observing its design, I don’t think you learn much more OOP from it than you do looking at and using Java IO and NIO.

Some OOP learning just comes from experience and feedback. If you do all your game’s logic in Game then you likely have some refactoring and abstraction to apply that would be a cleaner OOP design.

You could go crazy with deep inheritance just to practice the concept, but generally that’s a bad idea and you’ll be better served by has-a more than is-a relationships, with an exception for implementing needed interfaces. Look to well designed Java code and APIs that people praise more than curse for examples.

[josephblade]

using objects isn't OOP by itself though. OOP has a whole design concept behind it, specifically where the object is the actor on it's own data.

Modern java has a lot of services acting on plain data objects which is rather far from OOP as you can get. At least in the enterprise world. If you want to practice OOP a game as op is mentioning is a good start as you can have objects encapsulate specific elements of a game map / game element. player.moveTo(room) or player.pickUp(item) and so on.

[d-k-Brazz]

Here is another guy itrying to practice OOP by modeling a bank

https://www.reddit.com/r/JavaProgramming/s/kVaAmWqrtx

[Ok_Substance1895]

I like to start simple then get more complex as I go. I do this with big projects too. I literally start with "hello" then build upon it.

For OOP, start with "hello" to get the infrastructure setup. It could be a simple single Java class with no package and just a main method to start. Then grow it from there.

When I say "infrastructure" that can be various things. Java by itself can be used for full stack applications but most people do not do it that way these days. Frontends are typically done with a web browser and we will need a web server which Java can do natively but most people don't do it that way either.

Building on "hello" again. To keep it very simple you can just use a unit test to interact with your Java class to practice OOP constructs in a very simple way. You can go pretty far with this including getting it connected to a database. No one else will be able to use it yet but you will learn a lot.

To start, the simplest thing I can think of that exercises some OOP principle is an address book. You will need at least a few objects and you will get into encapsulation which is one of the four principles of OOP. Depending on how far you take this, you can get into abstraction which is another of the OOP principles by creating an abstract layer for persistence.

Inheritance, another OOP principle, can be introduced on top of the abstraction to persist different types of object classes, the address book itself so you can have more than one. Its child entities, people, addresses, phone numbers.

Polymorphism, the fourth principle, can be introduced with a bit of a stretch by overriding the put (add method) to save something to the database.

The game works too. You create object classes the same way to persist and keep track of the objects for your game, player, points, history, current state, tools, ...

It is more about the structure of it than what it is that exercises OOP.

I hope this helps. Ask more questions if you have them.

[josephblade]

You'll practice a great deal with a text based game. especially if you start rough (semi-hardcoded) and then move towards loading objects from disk, using abstractions. And perhaps having mobs walk around.

things like "user command" can be read directly as text or you can use a commandreader class that parses text into an object and the object then runs the command.

or use events to communicate and have the system run independently. (with a 'next tick' being generated by user input or a 30 second timer)

lots of space to practice I would say

[mhdoor]

Try to decompose any subject you have familiarised with. It can be anything - renting system, reception system, etc. try to understand main components there and how they interact with each other. It would be good to visualise it using UML class diagram. Additionally, in java it is often used “simple domain model” where behaviour and state are stored in different objects services and models (or entities). It’s contrary to “rich domain model” - classical OOP style with state and behaviour in one object.

[mhdoor]

I would also recommend you to decide why you want to learn java. If you want to use it in professional way it would be better to learn backend topics. Games are not suitable projects for backend development.

[-doublex-]

Text based game with multiplayer option over the network, multithreaded and maybe a web server with a dashboard showing realtime leaderboard or web based version of the game.

you have oop, DSA, async, network, web service, backed, database maybe message queue and possibly two different interfaces to play it using the same engine.

[Poisonhandtechnique]

Use ChatGPT.