Case Study II - Solution

COMP 1010 Home > Java Fundamentals

Introduction Introduction goes here.

{{{Body}}}

total = 0; total needs to be initialized before loop

Sample Solution Code

import javax.swing.*;
import java.util.Date;

/**
 *
 * This program will read in the first 9 digits of an ISBN and print out the 9 digits
 * along with the valid 10th check digit. This code uses a loop structure to remove redundant code
 * Note that this code will handle the possibility of the check digit being an 'X'.
 *
 * @author:     1010 Instructors
 * @version:    2007-September
 *
 */

public class CaseStudy2_ISBN_Solution  
{

    public static void main (String [] args) 
    {

        //variables declared here
        String temp;        //temporary input string
	int isbn;           //9-digit ISBN
	int digit;          //isolated ISBN digit
        int total = 0;      //total of isbn number when each digit is multiplied by check value
	int checkDigit;     //value of total%11(as per ISBN standard)

        //get input
	temp= JOptionPane.showInputDialog ("Enter first 9 digits of ISBN");
	isbn = Integer.parseInt (temp);

        System.out.println ("You have entered " + temp + ".\n\nThe weighted value of the ISBN is:");

	for (int i=9; i>0; i--) 
        {
            digit = isbn % 10;
	    isbn = isbn / 10;
	    total = total + digit * i;
	    System.out.println (digit + " * " + 9 + " for a running total of " + total);
	}
	
        //calculate check digit
        checkDigit = total % 11;

        System.out.println ("The weighted total is: " + total);

        //if check digit is equal to 10 then print an 'X', otherwise print the checkDigit value
	if (total%11 == 10) 
        {
	    System.out.println ("The check digit is: 'X'");
	    System.out.println ("\nThe 10-digit ISBN is: " + temp + 'X');
	}
	else 
        {
	    System.out.println ("The check digit is: " + total%11);
	    System.out.println ("\nThe 10-digit ISBN is: " + temp + checkDigit);
	}

	System.out.println ("\nProgrammed by COMP 1010 Instructors");
	System.out.println ("Date: " + new Date());
	System.out.println ("*** End of Processing ***");

    }//end main
}//end class

Links To Case Studies

Case Study I: Day One at Funky Books Inc.
Case Study II: Day Two at Funky Books Inc.
Case Study III: Day Three at Funky Books Inc.
Case Study IV: Day Four at Funky Books Inc.