Strongly typed, runs everywhere
Java
A statically typed, object-oriented language with a mature ecosystem. Common in large backends, Android apps and enterprise systems. This path has 13 lessons in reading order, from the basics to the ideas that come up in real code, with a runnable example in every lesson.
ModerateExamples verified with OpenJDK 21
- lessons
- 8 lessons
- exercises
- 0 exercises
- interview questions
- 0 interview questions
What Java is used for
- Enterprise backends
- Android apps
- Large-scale systems
- Big-data tooling
How examples are checked
Every example and every exercise solution was run with OpenJDK 21 at build time. In-browser execution for Java is not available yet; the pages say so rather than pretending.
Learn
The Java learning path
Read in order: each lesson leans only on the ones before it. Every lesson ends with a small program to write and links to matching exercises.
Practice
Practise Java
0 exercises across several topics, each checked by running your program against test cases. Start with these: