C++ Calculation Problem, Always returns $0 - c++

Question

I have to display and loop a menu, allowing the customer to make multiple orders for peanuts, movies, or books. The menu displays fine, but the quantity doesn't go down to the calculations part of my code. Everytime I enter a quantity for anything and checkout it returns $0. I have no idea why this is happening I don't see anything wrong with my code, but obviously there is. Do you guys have any suggestions on what to do based on looking at what I have?
#include <iostream>
#include <cstdlib>
using namespace std;
//function declarations
void displayMenu();
//constant statements
const double BOOK_PRICE = 9.00; //price per book
const double BOOK_SHIPPING = 1.06; //shipping per book
const double MOVIE_PRICE = 13.99; //price per movie
const double MOVIE_SHIPPING = .05; //shipping per movie subtotal
const double PEANUT_PRICE = 1.80; //price of peanuts per pound
const double SHIPPING_PRICE = .50; //shipping of peanuts per lb
int main()
{
//declaration statements
int numBooks = 0; //# of books purchased
int numMovies = 0; //# of movies purchased
double numPeanuts = 0.0; //# of peanuts per pound
double bookSubtotal = 0.0; //subtotal of books
double movieSubtotal = 0.0; //subtotal of movies
double peanutSubtotal = 0.0; //subtotal of peanuts
int totalBooks = 0; //running total of books
int totalMovies = 0; //running total of movies
double totalPeanuts = 0.0; //running total of peanuts
int userChoice = 0; //user input
double totalPrice = 0.0; //final price
while (userChoice != 4)
{
displayMenu();
cout << "Enter a menu choice: ";
cin >> userChoice;
if (userChoice == 1)
{
cout << "Please enter the number of books: ";
cin >> numBooks;
totalBooks = totalBooks + numBooks;
}
else if (userChoice == 2)
{
cout << "Please enter the number of movies: ";
cin >> numMovies;
totalMovies = totalMovies + numMovies;
}
else if (userChoice == 3)
{
cout << "Please enter the pounds of peanuts as a decimal: ";
cin >> numPeanuts;
totalPeanuts = totalPeanuts + numPeanuts;
}
else if (userChoice == 4)
{
break;
}
else
{
cout << "Invalid Input" << endl;
}
}
//computations
bookSubtotal = (totalBooks * BOOK_PRICE) + (totalBooks * BOOK_SHIPPING);
movieSubtotal = (totalMovies * MOVIE_PRICE * .05) + (totalMovies * MOVIE_PRICE);
peanutSubtotal = (PEANUT_PRICE * totalPeanuts) + (totalPeanuts * .5);
totalPrice = bookSubtotal + movieSubtotal + peanutSubtotal;
cout << "The total price is $" << totalPrice << endl;
system("PAUSE");
return 0;
}//end of main
void displayMenu()
{
cout << "1 Books" << endl;
cout << "2 Movies" << endl;
cout << "3 Peanuts" << endl;
cout << "4 Checkout" << endl;
}//end of displayMenu

Answer 1

The problem is in the cin >> - you found the answer yourself when you say that the book count is zero. I suggest you try to put << endl after each cout << .... Other solution is to use _flushall(); after each cout.