Variable won't store data - c++

Question

for some reason my subtotal variable doesn't store the prices of the items inputted by the user any suggestions? I don't know if I set up my loop wrong or if the subtotal has to be put outside the if else statements but then I don't know how I would know what to store from users input
#include <iostream>
#include <iomanip>
#include <string>
#include <fstream>
#include <cstdlib>
using namespace std;
const double tax_rate = 0.05;
struct menuItemType
{
string ItemName;
double ItemPrice;
};
void getData(ifstream &in, menuItemType menuList[]);
void showMenu(menuItemType menuList[]);
void printCheck(menuItemType menuList[]);
int main()
{
menuItemType menuList[10];
menuList[10].ItemName;
menuList[10].ItemPrice;
ifstream in;
in.open("Menu.txt");
cout << "Welcome to Johnny's Breakfast Diner!" << endl;
getData(in,menuList);
showMenu(menuList);
return 0;
}
void getData(ifstream &in, menuItemType menuList[])
{
int i = 0;
while (!in.eof())
{
in >> menuList[i].ItemName >> menuList[i].ItemPrice;
i++;
}
}
void showMenu(menuItemType menuList[])
{
int j = 0;
char answ;
cout << fixed << setprecision(2);
cout << "Would you like to take a look at our menu? (Y/N)";
cin >> answ;
if (answ == 'Y' || answ == 'y')
{
cout << left << setw(10) << "Item#" << left << setw(15) << "Item" << left << setw(18) << "Price" << endl;
do {
{
cout << left << setw(8) << j << " " << left << setw(15) << menuList[j].ItemName << " " << "$" << menuList[j].ItemPrice << endl;
j++;
}
} while (j < 8);
printCheck(menuList);
}
else if (answ == 'N' || answ == 'n')
{
system("cls");
cout << "Have a good day!" << endl;
}
}
void printCheck(menuItemType menuList[])
{
char answ;
int choice;
bool menu = true;
double subtotal = 0;
double tax = (subtotal * tax_rate);
double total = (tax + subtotal);
cout << "Would like to place your order (Y/N)";
cin >> answ;
if (answ == 'Y' || answ == 'y')
{
cout << "Please enter the number of the item, 8 to finish order:";
do {
cin >> choice;
if (choice == 0)
{
cout << menuList[0].ItemName << " " << "$" << menuList[0].ItemPrice << endl;
subtotal = subtotal + menuList[0].ItemPrice; \\ for some reason here it doesn't store the prices have no idea why
}
else if (choice == 1)
{
cout << menuList[1].ItemName << " " << "$" << menuList[1].ItemPrice << endl;
subtotal = subtotal + menuList[1].ItemPrice;
}
else if (choice == 2)
{
cout << menuList[2].ItemName << " " << "$" << menuList[2].ItemPrice << endl;
subtotal = subtotal + menuList[2].ItemPrice;
}
else if (choice == 3)
{
cout << menuList[3].ItemName << " " << "$" << menuList[3].ItemPrice << endl;
subtotal = subtotal + menuList[3].ItemPrice;
}
else if (choice == 4)
{
cout << menuList[4].ItemName << " " << "$" << menuList[4].ItemPrice << endl;
subtotal = subtotal + menuList[4].ItemPrice;
}
else if (choice == 5)
{
cout << menuList[5].ItemName << " " << "$" << menuList[5].ItemPrice << endl;
subtotal = subtotal + menuList[5].ItemPrice;
}
else if (choice == 6)
{
cout << menuList[6].ItemName << " " << "$" << menuList[6].ItemPrice << endl;
subtotal = subtotal + menuList[6].ItemPrice;
}
else if (choice == 7)
{
cout << menuList[7].ItemName << " " << "$" << menuList[7].ItemPrice << endl;
subtotal = subtotal + menuList[7].ItemPrice;
}
else if (choice == 8)
{
break;
}
}while(menu = true);
cout << "Taxes" << "$" << tax << endl;
cout << "Amount Due" << "$" << total << endl;
}
else if (answ == 'N' || answ == 'n')
{
system("cls");
cout << "Ok, maybe I can help you at a later time." << endl;
}
}

Answer 1

It looks like you're trying to use subtotal before you've actually put data into it.
The problem is these lines:
double tax = (subtotal * tax_rate);
double total = (tax + subtotal);
At that point in the program, subtotal still contains the initial value, which is 0, so the result of those calculations is also 0. You need to put those lines after the loop so that they work with the final value of subtotal.

Answer 2

What's the result. the subtotal will have
menuList[choice].ItemPrice value
if you want to change
subtotal += menuList[choice].ItemPrice;