//
// File:  /home/cs255001/demo/atoi/JavaInput_5.java
//
// Read in 1 character and convert char into int (2s compl) 
//
// We use the **most general method (an IF statement)** by:
//
//    Look up each symbol and map the digit to its assigned numeric value
//

import java.util.Scanner;

public class ConvStr1DigitGen
{
   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() > 1 )
         {
            System.out.println("Error: you must type 1 digit !");
            System.out.println("Try again\n");
            continue;
	 }

         System.out.println("ASCII codes (in decimal) = " + (int) s.charAt(0) );

 	 if ( s.charAt(0) == '0' )
            x = 0;
 	 else if ( s.charAt(0) == '1' )
            x = 1;
 	 else if ( s.charAt(0) == '2' )
            x = 2;
 	 else if ( s.charAt(0) == '3' )
            x = 3;
 	 else if ( s.charAt(0) == '4' )
            x = 4;
 	 else if ( s.charAt(0) == '5' )
            x = 5;
 	 else if ( s.charAt(0) == '6' )
            x = 6;
 	 else if ( s.charAt(0) == '7' )
            x = 7;
 	 else if ( s.charAt(0) == '8' )
            x = 8;
 	 else if ( s.charAt(0) == '9' )
            x = 9;
         else
         {
            System.out.println("Input '"+s.charAt(0)+"' is NOT a digit !\n");
            continue;
         }

	 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\n");
      }
   }
}