World 23 of 26 · Advanced

🚀 Modern Java 17 → 25

10 Java concepts, each explained step by step with real code, a common trap and practice questions.

  1. Pattern matching for switchcase Circle c ->, guards with when, null cases.
  2. Record patternsDeconstructing records: case Point(int x, int y).
  3. Sealed hierarchies + exhaustive switchAlgebraic data types with no default branch needed.
  4. Unnamed variables & patternsJava 22 _ for unused variables and pattern components.
  5. Flexible constructor bodiesJava 25: statements before super(...) that don't use this.
  6. Data-oriented programmingCombining records, sealed types and patterns to model data.
  7. Helpful NullPointerExceptionsMessages that name exactly which reference was null.
  8. Text blocks & switch expressions recapModern replacements for older idioms.
  9. Preview & incubator features--enable-preview, how features graduate (e.g. primitive patterns, structured concurrency).
  10. Migrating legacy codeJava 8 → 25 upgrade benefits and removed APIs (finalization, Security Manager).