/**
 * A simple cash register program
 *  Program will repeatedly prompt (ask) if user has any more items to purchase
 *      if yes, user is prompted for unitPrice, quantity
 *          and a subtotal is output
 *      if no, then loop terminates and the total is printed out
 *      
 *  This program will demonstrate various forms of input AND output!!
 */

import java.util.*;

public class CashRegister
{
    public static void main(String[] args)
    {
        Scanner sc=new Scanner(System.in);
        int quantity;
        double unitPrice;
        String keepGoing;
        double total=0.0;
        
        keepGoing="Y";          // need an initial value for keepGoing
                                // so that boolean expression inside while
                                // makes sense. This assumes there is at least 1 item
        
        while(keepGoing.toUpperCase().equals("Y"))  
        {
            System.out.print("\nEnter unit price: ");   //Prompt for unit price and input
            unitPrice=sc.nextDouble();
            
            
            System.out.print("Enter quantity :");       //Prompt for qunatity and input
            quantity=sc.nextInt();
            
            sc.nextLine();                              // why is this here ??? Read book or come to class for answer!
            
            System.out.printf("\nSubtotal : %8.2f\n",unitPrice*quantity);
            total=unitPrice*quantity;                   //update total
            
            System.out.print("Do you want to continue [Y/N]: " );
            keepGoing=sc.nextLine();
        } 
        
        System.out.printf("\nTotal Due : %9.2f",total); //print out total due
        
    }
}