Learn to Code in 7 days

Seven days per course · Your own pace

Learn Java.Build a strong foundation.

Write your first complete program, learn to think in methods and objects, and bring several source files together into a working application. Every step includes code you can change and run.

Start Day 1 Explore the course
Public course
1
Lessons
36
Days per course
7
Installs needed
0
Try it here — press Run Java
public class Main { public static void main(String[] args) { // Change a duration, then press Run. int[] sessions = {25, 10, 15}; int total = 0; for (int minutes : sessions) { total += minutes; } System.out.println("Planned: " + total + " minutes"); } }

Change 25 to 30 and run again. Day 1 explains the frame around the instructions.

Find your starting point

Your first week of Java.

Start from zero. You do not need Python, JavaScript or any other programming language. Every available course is public, with no sign-in required.

01 / BeginnerPublic

Beginner Java

Your first programming course

From printing your first message to building a tested application with its own objects and separate source files.

  • Variables, conditions, loops and methods
  • Arrays, lists, classes and private state
  • Input validation, exceptions and tests
You will buildMulti-file study planner

36 lessons · 7 days

Explore beginner

Beginner is available now. Intermediate and advanced Java courses are not available yet.

More than a page to read

A little explanation. Plenty to try.

You learn a rule by using it. Each day gives you chances to predict, experiment and solve a problem with less help.

Learn by changing code

Read a short explanation, predict the output and run the example. Change an input to find out whether you understood the rule.

Get help in small steps

Try each exercise first. Open an idea hint, then a first-step hint if you need it. Compare your approach with the worked solution afterward.

Build beyond the example

Use checkpoints to work independently. Finish a project, tackle a different brief and return a few days later to practise from memory.

Beginner, day by day

Seven steps to a working project.

Plan around 60–90 minutes of active study per day. Split a day into smaller sessions when needed; the order matters more than the calendar. Delayed review is extra.

  1. Day 1 · 5 lessons

    Your First Programs

    Run Java, name values and explain numbers and text.

  2. Day 2 · 5 lessons

    Decisions & Loops

    Choose branches and trace bounded repetition.

  3. Day 3 · 5 lessons

    Methods & Small Checks

    Break a problem into methods and verify their results.

  4. Day 4 · 5 lessons

    Arrays & Lists

    Store, traverse and summarize groups of values.

  5. Day 5 · 5 lessons

    Objects & Source Files

    Model independent objects and connect classes in separate files.

  6. Day 6 · 5 lessons

    Input, Validation & Errors

    Read input, reject invalid values and test recovery.

  7. Day 7 · 6 lessons

    Build a Study Planner

    Run, test and extend a complete multi-file Java application.
See every beginner lesson

Something to show for your work

A project you can explain.

By the end of beginner, the pieces come together in a multi-file study planner. You will know where the data lives, how it changes and how to check the result.

Switch between Main.java and helper classes, run the model checks and download the sources for optional local work. Then transfer the ideas to a reading tracker.

Explore the final day

Your first experiment

Planned: 50 minutes

The small example at the top already uses the same idea: store a few sessions and derive a useful total. The course teaches each piece before asking you to build the complete planner.

About the browser editor

A Java 25 subset runs in this browser. The course introduces supported features in order; installing a full JDK is an optional Day 7 step.

Before you begin

A few useful answers.

Start with the right expectations, then spend your time making things work.

Is Java the same as JavaScript?

No. They are different languages. Neither beginner course requires the other. Choose Java if you want to begin with explicitly typed programs, classes and objects.

Do I have to install Java?

No. All core practice runs in the browser, including the multi-file planner. Day 7 offers source downloads and optional instructions for compiling the same project with a local JDK.

Can I edit more than one source file?

Yes. Later lessons supply named source tabs such as Main.java and Session.java. You can edit both and run the program through its marked entry point.

What comes after beginner?

Intermediate and advanced Java courses are not available yet. Finish the independent reading-tracker brief, return for delayed review and try extending your downloaded project.

Start with one small program

You can run your first example today.

No setup checklist. Open Day 1, change a line and see what happens. The rest can follow one lesson at a time.

Start learning Java Open the scratch pad