JavaCourse 1 of 2 · Java Mastery

The Fundamentals

Java from your first compiled program to arrays, collections, and real error handling.

4 sessions
60 min each
Beginner

No coding experience needed
Browser editor or a JDK and VS Code
Certificate when you finish both courses

Course overview

What you'll learn

What the JDK and the JVM are, your first class with main(), compiling and running, comments, and reading compiler errors.
Static types, primitives and objects, operators, printf, constants, casting and wrapper classes, ending in a receipt printer.
if and switch expressions, loops, arrays, ArrayList and HashMap, and a small gradebook.
Methods and overloading, passing arrays, try/catch and Scanner, ending in a command-line grade tracker.

Who this course is for

Complete beginners: you need no coding experience.
You learn best by writing the code yourself, not by watching videos.
You want feedback on your own code, at your own pace, one hour at a time.
You would rather start in the browser than install tools first.

Course syllabus

4 sessions
24 blocks of 10 min
4 hours

Each session is one hour with the AI tutor and uses one credit. Sign in to start.

Session 1NextJava & Your First ProgramWhat the JDK and the JVM are, your first class with main(), compiling and running, comments, and reading compiler errors.
1. Welcome and setup10 min
2. Your first program10 min
3. Compile, run, and print10 min
4. Comments and compiler errors10 min
5. Mini project: your "about me" card10 min
6. Final check and wrap-up10 min
Start session
Session 2Variables, Types & OperatorsStatic types, primitives and objects, operators, printf, constants, casting and wrapper classes, ending in a receipt printer.
1. Welcome back and variables10 min
2. Types and operators10 min
3. Printing neatly with printf10 min
4. Constants, casting and wrapper classes10 min
5. Mini project: a shop receipt10 min
6. Final check and wrap-up10 min
Start session
Session 3Control Flow, Arrays & Collectionsif and switch expressions, loops, arrays, ArrayList and HashMap, and a small gradebook.
1. Welcome back and decisions with if10 min
2. Switch expressions10 min
3. Loops and arrays10 min
4. ArrayList10 min
5. Mini project: a gradebook10 min
6. Final check and wrap-up10 min
Start session
Session 4Methods & a Grade TrackerMethods and overloading, passing arrays, try/catch and Scanner, ending in a command-line grade tracker.
1. Welcome back and your first methods10 min
2. Overloading10 min
3. Arrays as parameters10 min
4. Errors with try/catch, and input with Scanner10 min
5. Capstone: a command-line grade tracker10 min
6. Final check and wrap-up10 min
Start session

How the tutor teaches

The same three rules in every session, from the first line of code to the last.

Practice, not videos

You write all of the code. The tutor reacts to what you actually typed, line by line.

Hints, not answers

A ladder from a light nudge to the solution, and only after you have made a real attempt.

Real output, never invented

Your code runs for real. The tutor reads what the machine showed, and trusts it.

Keep the momentum going

The next course of Java Mastery, and where the other paths begin.

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Errors you may meet in this course

Java

Java: incompatible types: String cannot be converted to int, and how to fix it

Fix Java's "incompatible types: String cannot be converted to int" (also shown with java.lang.String): nextLine() and Integer.parseInt, the nextInt() trap, and the related int to String, double, char and lossy conversion errors.

21 October 2026 · 8 min read

Frequently asked questions

What students ask before they start The Fundamentals.

Do I need to install anything?

Not for this course. The editor in the page runs your code next to the chat. If you prefer, you can use a JDK and VS Code on your own computer.

What if I get stuck?

The tutor gives a ladder of hints, from a light nudge to the solution, and only after you have made a real attempt.

Do I keep my code?

Yes. In the editor in the page, your project is saved on the server for this course, continues in your next session on any device, and downloads as a .zip.

Do I get a certificate?

Yes, for the whole path. When you have finished all 2 courses of Java Mastery (this is Course 1), you get the Java Mastery certificate of completion with your name: a link anyone can check, one-click LinkedIn and a PDF. Your progress towards it is on your dashboard.

Do I need anything from before?

No. This course starts from zero. Take the sessions in order: each one builds on the one before.

Meet the tutor in a free 20-minute session.

Twenty minutes with the tutor, right in your browser. No card, nothing to install.

Start the free trial

A session: the tutor's chat on the left, the code editor with a Java program and its output on the right