SilvioCavalcantiBonfim/fullcycle-imersao16-java21

Java 21

• Record Patterns - instanceOf pattern matching for Records
• Pattern Matching for Switch
• String templates
• Virtual Threads

Pattern Matching for Switch

• Selector Expression Type

  record Point(int x, int y) { }
  
  enum Color { RED, GREEN, BLUE }
  
  static void typeTester(Object obj) {
      switch (obj) {
      case String s -> {
              if (s.length() == 1) {
                  System.out.println("Short: " + s);
              } else {
                  System.out.println(s);
              }
              break;
      }
      case Color c  -> System.out.println("Color with " + c.values().length + " values");
      case Point p  -> System.out.println("Record class: " + p.toString());
      case null, default       -> System.out.println("Something else");
      }
  }

• When clauses

  record Point(int x, int y) { }
  
  enum Color { RED, GREEN, BLUE }
  
  static void typeTester(Object obj) {
      switch (obj) {
      case String s when s.length() == 1 -> System.out.println("Short: " + s);
      case String s                      -> System.out.println(s);
      case Color c  -> System.out.println("Color with " + c.values().length + " values");
      case Point p  -> System.out.println("Record class: " + p.toString());
      case null, default       -> System.out.println("Something else");
      }
  }