Nesting a class within a scope. : Nested Classes « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. Nested Classes

public class MainClass {
  private void method(boolean b) {
    if (b) {
      class A {
        private String id;

        A(String s) {
          id = s;
        }

        String getSlip() {
          return id;
        }
      }
      A ts = new A("slip");
      String s = ts.getSlip();
    }
    // Can't use it here! Out of scope:
    // ! A ts = new A("x");
  }

  public void track() {
    method(true);
  }

  public static void main(String[] args) {
    MainClass p = new MainClass();
    p.track();
  }
}