Learn Java

Java is a widely-used, object-oriented, platform-independent language ("write once, run anywhere"). It powers a large share of enterprise backend systems, Android applications, and large-scale server software, and is a common choice for university programming courses.

What this path covers

25 chapters, in reading order: values and syntax, control flow, functions, collections, objects, error handling, and a small combined project, followed by intermediate topics (debugging, files, APIs, async, project structure, state) and advanced topics (architecture, testing, security, performance, deployment, and a full real-project walkthrough).

Start here

Java foundations — The mental model for reading a program: values, statements, output, and program flow.

Full chapter list

  1. Java foundationsBeginner
  2. Java syntax and data typesBeginner
  3. Java variables and valuesBeginner
  4. Java operators and expressionsBeginner
  5. Java conditions and decisionsBeginner
  6. Java loops and repetitionBeginner
  7. Java functions and reusable logicBeginner
  8. Java arrays, lists, maps, and setsBeginner
  9. Java objects and classesBeginner
  10. Java error handling and debuggingBeginner
  11. Java basic projectBeginner
  12. Java debugging step by stepIntermediate
  13. Java files, JSON, and local dataIntermediate
  14. Java APIs and HTTPIntermediate
  15. Java async programmingIntermediate
  16. Java project structure and modulesIntermediate
  17. Java state managementIntermediate
  18. Java best practices and clean codeIntermediate
  19. Java software architectureAdvanced
  20. Java testing behaviorAdvanced
  21. Java security foundationsAdvanced
  22. Java performance and measurementAdvanced
  23. Java deployment and releaseAdvanced
  24. Java real project walkthroughAdvanced
  25. Java real-world patterns and advanced conceptsAdvanced
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