//******************************************************
// Program Name: spherestats.java
// Author: Pat Moss
// Date: Sept 17, 2005  Rev: 01
//
// Input sphere radius. Then calculate volume and area.
//******************************************************

import java.util.Scanner;

public class spherestats
{
 public static void main (String[] args)
 {
  float sphereradius = 0;
  Scanner scan = new Scanner(System.in);

  System.out.println ("spherestats.java by pat moss");
  System.out.println ("");

  System.out.print ("Enter a positive float value for sphere radius (0 to quit): ");
  sphereradius = scan.nextFloat();

  while (sphereradius != 0)  // Use the sentinel value of 0 to terminate the loop
  {
   if(sphereradius < 0)
   {
	System.out.println ("Invalid input value. Please reenter a positive float value.");
   }
   else
   {
   double spherevolume = (double) 4 / 3 * Math.PI * Math.pow (sphereradius, 3);
   double spherearea = 4.0D * Math.PI * Math.pow (sphereradius, 2);

   System.out.println ("The sphere volume is " + spherevolume);
   System.out.println ("The sphere area   is " + spherearea);
   System.out.println ("");
   }

   System.out.println ("");
   System.out.print ("Enter a positive float value for sphere radius (0 to quit): ");
   sphereradius = scan.nextFloat();
  }

  System.out.println ("All Done...");

 }
}