//
// File:  /home/cs255001/demo/atoi/JavaInput_4.java
//
// Read in negative number of 1 digit and add 1 to the input
//

import java.util.Scanner;

public class ConvStr1DigitNeg
{
   public static void main(String[] args)  throws Exception
   {
      Scanner in = new Scanner(System.in);
      String  s  = null;
      int     x  = 0;

      while ( true )
      {
         System.out.print("Enter input: ");

         s = in.next( );     // Read a String from key board

         if ( s.length() != 2 || s.charAt(0) != '-' )
         {
            System.out.println("Error: you must enter a 1 digit neg number !");
            System.out.println("Try again\n");
            continue;
	 }

         System.out.println("ASCII codes (in decimal) = " + (int) s.charAt(1) );

	 x = s.charAt(1) - '0';	 // '0' = 48, so we subtract 48 

         x = -x;                 // Get the negative value

	 System.out.println("integer value x = " + x);

         /* =============================================================
            Proof this is an integer that you can use in computation
            ============================================================= */
	 x = x + 1;

	 System.out.println("\nPerforming a calculation with the output:");
	 System.out.println("After adding 1, x = " + x + "\n");
      }
   }
}