Inner Classes

• Trivial class can be defined inside a method

  public class DataSetTester3
  {
     public static void main(String[] args)
     {
        class RectangleMeasurer implements Measurer
        {
           . . .
        }
        Measurer m = new RectangleMeasurer();
        DataSet data = new DataSet(m);
        . . .
     }
  }

• If inner class is defined inside an enclosing class, but outside its methods, it is available to all methods of enclosing class
• Compiler turns an inner class into a regular class file:
  DataSetTester$1$RectangleMeasurer.class