How to use CodeGym - 1

"Hi, Amigo. My name is John Squirrels, Captain of the Galactic Rush."

"Good day, Captain."

"Let me explain to you how the learning process works, as well as how to use our services."

"Our primary goal is to have tons of fun while acquiring practical programming skills, which will make it easy to get a job as a programmer. To accomplish this, we use practice exercises. A lot of them. Seriously, a lot."

How It All Works

The whole course is divided into four units, or quests: AP Java Exam Prep (Java Basics), Java Core, Java Multithreading, and Java Collections. Each quest consists of a number of levels, and each level contains 10-15 lessons and 20-30 exercises.

For each task you complete, you’ll be rewarded with a few units of dark matter. To progress in your quest, you’ll need dark matter to unlock new levels and lessons.

You can complete the tasks any way you’d like. You can work on them while reading the lessons, or first read the lessons until you understand them and then work on the exercises separately. Whatever works best for you.

Advancing to the Next Level or Lesson

To advance to the next lesson or level, you need to collect enough "dark matter" to "pay" to unlock it. It looks something like this:

Within a quest, you must unlock lessons in order. You can’t just skip to the middle of the course and try something there. However, once unlocked, a lesson is always accessible. You can go back to it at any time to reread it or review the examples again.

Also, as I mentioned earlier, you can earn dark matter by completing tasks. The description of each task says how many units you'll receive for completing it. For example, you’ll earn 1 unit of dark matter for the following task.


On CodeGym, you'll find a ton of different exercises. I'll list the main types here.

Copy code from an example — This is the simplest exercise. To complete it, you need to enter the Java code in the bottom window exactly as it appears in the top window.

Write a program — These are the most important exercises in the course. These can vary greatly in their complexity: all the way from short and simple tasks to puzzlers that will really put your brain to work... You can start working on any task marked as "Available". To start one, just click the "Open" button on the task description.

This will open the Web IDE. The first tab contains the task conditions. The second tab is where you type your code.

To check if you've successfully completed the task, you'll need to click the "Verify" button. This will send your program to our servers for verification and then show you the results.

Create mini projects — These are the most interesting and challenging exercises! A mini-project consists of a series of interconnected sub-tasks. By the end, you will have created your very own little project, such as a game. But before you get to create your first mini-project, you’ve got a lot of work to do. You won’t see your first mini-project until the end of Java Core quest.

Nerd Break — These are the hardest exercises of them all! Just kidding! Most often, a "break" involves watching a cool tech-related video. And yes, you still get a dark matter reward for these exercises too.

P.S.: Starting with Level 3, you’ll be able to work on tasks using an integrated development environment (IDE) called IntelliJ IDEA. A lesson will teach you how it’s done, but we’ll tell you more about that later.

Lessons and task statuses

Tasks can have the following statuses. "Available" — Go ahead and try to complete it!

"Completed" — You successfully completed this task and collected your dark matter less than three days ago. You can try to solve it again to improve your solution.

"Closed" — You successfully completed this task and collected your dark matter more than three days ago. You can no longer submit this task for verification.

"Locked" — I think this is pretty self-explanatory. To access the task, you’ll need to unlock the lesson associated with it. And that will require that you unlock all the lessons leading up to this one.

Lessons have two possible statuses: "Available" and "Locked".

The last "available" lesson before a long chain of "locked" lessons is the one you stopped on. If you click on the first "locked" lesson, you will be prompted to pay a certain amount of dark matter to unlock it.