calculation in loop - Java

Question

I am not able to calculate the price a customer pays based on the number of bottles they have bought. It keeps returning a value of $14 for any amount of bottles purchased. Please see Java code below:

// PriceCalculator class that calculates the prices for customers
// counter controlled repetition

import java.util.Scanner; // program uses class Scanner

public class PriceCalculator
{
private String beginSale; // name of shop this price is calculated

// constructor initializes beginSale
public PriceCalculator( String name )
{
    beginSale = name; // initializes shopName
} // end constructor

// method to set the shop name
public void setBeginSale (String name )
{
    beginSale = name; // set the welcome address
} // end method setBeginSale

// method to retrieve the welcome address
public String getBeginSale()
{
    return beginSale;
} // end method getBeginSale

// display a welcome message to the shopper
public void displayMessage ()
{
    // getBeginSale gets the thank you address
    System.out.printf( "Welcome to Price Calculator for Purchasing Wines at %s!\n",
        getBeginSale() );
} // end method displayMessage

// determine charges based on 5 customers who shopped
public void calculatePrice()
{
    // create scanner to obtain input from command window
    Scanner input = new Scanner( System.in );

    int basePrice; // base price of a bottle of wine
    String customer; // name of customer
    int gradeCounter; // number of customers to be entered next
    int bottles; // number of bottles purchased
    double discount; // discount value on the number of bottles
    double rate;
    double total; // total costs of wine purchased

    // initialization phase
    basePrice =  10; // initialize base price
    gradeCounter = 1; // initialize loop counter
    bottles = 1; // initialize bottles
    discount = (basePrice * bottles); // initialize discount
    rate = 0;
    customer = null; // initialize customer name

    // processing phase uses counter-controlled repetition
    while ( gradeCounter <= 3 ) // loop 5 times
    {
        System.out.print( "Enter the name for customer " + gradeCounter + " : " ); // prompt
        customer = input.next(); // input next name
        System.out.print( "Enter the number of bottles for customer " + gradeCounter + " : "); // prompt
        bottles = input.nextInt(); // input next bottles sold
        gradeCounter = gradeCounter + 1; // increment counter by 1
        discount = (basePrice * bottles) - (rate * bottles);

        System.out.printf( "\nThe Price for Customer - %s is : $%.2f\n\n",
            customer, discount );
    } // end while loop

    // calculate purchase based on number of bottles sold

    if ( bottles <= 6 )
    {
        discount = (basePrice * bottles) - (rate * bottles); // calculates discount
    }
    else if 
    ( bottles > 6 && bottles<= 12 )
        {
        discount = (basePrice * bottles) - (rate * bottles); // calculates discount
        }
    else if ( bottles > 48 )
        System.out.println ( "It is forbidden to sell above the maximum range");

} // end method calculatePrice
} // end class PriceCalculator

Answer 1

Change || to &&

if (bottles > 6 || bottles <= 12) // Your code

if (bottles > 6 && bottles <= 12) // changes

Answer 2

It's simple; you are printing the price in the loop where you input data so the price doesn't change and the same statement is printed again and again.

Just move following statements:

System.out.printf( "\nThe Price for Customer - %s is : $%.2f\n", customer, discount );
} // end while loop

post this line:

System.out.println( "It is forbidden to sell above the maximum range" );

The output will be:

Welcome to Price Calculator for Purchasing Wines at Red Rocky!
Enter the name for customer 1: asdfsa
Enter the number of bottles for customer 1: 3

The Price for Customer - asdfsa is : $42.00
Enter the name for customer 1: gasdfs
Enter the number of bottles for customer 1: 4

The Price for Customer - gasdfs is : $56.00
Enter the name for customer 1: asfasdf
Enter the number of bottles for customer 1: 5

The Price for Customer - asfasdf is : $70.00

Also you can replace this statement

System.out.print( "Enter the name for customer 1: " );

with

System.out.print( "Enter the name for customer " + gradeCounter + ":");

Final Code would look like:

while (gradeCounter <= 3) // loop 3 times
{
    System.out.print("Enter the name for customer 1: "); // prompt
    customer = input.next(); // input next name
    System.out.print("Enter the number of bottles for customer 1: "); // prompt
    bottles = input.nextInt(); // input next bottles sold
    gradeCounter = gradeCounter + 1; // increment counter by 1
// calculate purchase based on number of bottles sold
    if (bottles <= 6) {
        discount = (basePrice * bottles); // calculates discount
    } else if (bottles > 6 || bottles <= 12) {
        discount = discount * 0.05 * bottles * basePrice; // calculates discount
    } else if (bottles > 48)
    System.out.println("It is forbidden to sell above the maximum range");
    System.out.printf("\nThe Price for Customer - %s is : $%.2f\n",customer, discount);
} // end while loop

Answer 3

You want to change your

if (bottles > 6 || bottles <= 12)

to

if (bottles > 6 && bottles <= 12)

Answer 4

You are not changing any values... First, you set the value of discount:

discount = (basePrice * bottles); // initialize discount

Then in the while loop, it never is updated based on the values given:

System.out.printf( "\nThe Price for Customer - %s is : $%.2f\n",
        customer, discount );

Shouldn't the discount value be set inside the while loop before the printf? :)

Or to be more clear:

    // processing phase uses counter-controlled repetition
while ( gradeCounter <= 3 ) // loop 3 times
{
    System.out.print( "Enter the name for customer 1: " ); // prompt
    customer = input.next(); // input next name
    System.out.print( "Enter the number of bottles for customer 1: "); // prompt
    bottles = input.nextInt(); // input next bottles sold
    gradeCounter = gradeCounter + 1; // increment counter by 1
discount = (basePrice * bottles);
    System.out.printf( "\nThe Price for Customer - %s is : $%.2f\n",
        customer, discount );
} // end while loop