CodeGym offers several quests: Java Syntax, Java Core, Java Collections, and Multithreading. It is a well-structured course covering all key aspects of Java. You'll find more than 500 mini-lessons and 1200 practical tasks.

We teach students to code in IntelliJ IDEA, one of the most convenient and popular IDEs for Java. To make life easier for you, we wrote a CodeGym plugin for IntelliJ IDEA. It lets you get a task in two clicks, and submit it for verification in one!

What's wrong this time? Where's my mistake? Why doesn't my solution work correctly? Get answers to these questions from status indications for each task requirement. After submitting your solution for verification, you'll see which task requirements you have fulfilled and which you have not.

Task recommendations are based on an analysis of tens of thousands of errors made by previous CodeGym students. When our system recognizes an error, you'll automatically receive a recommendation from the programmer whose wrote the task. It's almost like working with a personal mentor.

In ordinary full-time courses, the teacher is inundated with a huge number of student programs. He or she is physically incapable of carefully and quickly checking everything. Students have to wait a long time! CodeGym has no such problem: our validator checks your solution instantly. Click a button, and in a couple of seconds you'll know whether your solution is correct. If you made a mistake, you'll get a list of requirements and recommendations on what exactly needs to be fixed.

It's difficult for beginners to write large programs, since they don't know how to approach them. That's why we invented mini-projects consisting of 15-20 subtasks. Each subtask has detailed instructions on what to do. This lets you gain experience developing relatively complex applications. For example, you will write simple games, an online chat system, a restaurant automation system, and much more.

Tasks for future programming rock stars! They are more difficult than ordinary tasks and require much more time and effort, even if you're cruising through your studies. Bonus tasks are devoted to algorithms, patterns, and other topics that many people find difficult.