public class ThrowException
{
   public static void main(String[] args)
   {

       double area = areaOfCircle( -4 );

   }

   public static double areaOfCircle( double radius )
   {
      if ( radius < 0 )
         throw new RuntimeException("***neg radius***"); 
                                            // Returns an exception code
      else
         return 3.1415 * radius * radius;
   }
}