public class Input2
{

   /* -------------------------------------------------------
      Pass information to method with class variable x
      ------------------------------------------------------- */
   public static double x;


   /* ----------------------------------------------------------
      Notice that the method does not have any parameter var !
      ---------------------------------------------------------- */
   public static double Square( )                
   {
      double out;

      out = x * x;          // x contains input information

      return(out);
   }

   public static void main( String[] args )
   {
      double a, b;

      a = 4.0;

      x = a;             // The value in a is passed using class var x
      b = Square( );   

      System.out.println( b) ;
   }
}