Thread: Vending Machine Simulation Successfully Executed, but still not Right

Hello everyone, I made a program that simulates a vending machine for class. I finally got it to execute without any errors, yet something is not right. I have functions that are being called upon when they shouldn't be. For instance, I choose my items, and it asks me if I want to pay with 1 debit or 2 credit. If I enter 3 it displays 'Invalid option please try again' at which point the program is supposed to stop, but instead, it goes straight to the creditcard function and says Enter PIN.

Alternatively, if I choose my items, and select 1 for debit payment, it asks me to enter the PIN. The PIN has to be 1234, and if I enter that its suppose to go straight to the receipt function, but instead it again goes to the creditcard function and asks Enter ZIP. I have my code so that if payment option == 1, it goes to the void debitcard function, why is it calling upon the void creditcard function as well?

Code:

#include <iostream>
#include <functional>
using namespace std;

	int option;
	double chips, milk, cola, coffee, total, zipcode, quantity_chips, 
		   quantity_milk, quantity_cola, quantity_coffee, payment, pin, error, tax, final_cost;

void menu ()
{
	cout << "Welcome to CSUMB Vending Machine.\n";

	do {
		cout << "Select from our menu:\n"
			 << "\t1. Sun Chip........$1.50\n"
			 << "\t2. Otter Milk......$2.00\n"
			 << "\t3. CSUMB Cola......$1.00\n"
			 << "\t4. Regular Coffee..$2.50\n"
			 << "\t5. Check out\n";

		cout << "Enter your option: ";
		cin >> option;

			switch (option)
			{
			case 1:
				cout << "Quantity: ";
				cin >> quantity_chips;
				chips = (1.5 * quantity_chips);
				break;

			case 2:
				cout << "Quantity: ";
				cin >> quantity_milk;
				milk = (2 * quantity_milk);
				break;

			case 3:
				cout << "Quantity: ";
				cin >> quantity_cola;
				cola = (1 * quantity_cola);
				break;

			case 4:
				cout << "Quantity: ";
				cin >> quantity_coffee;
				coffee = (2.5 * quantity_coffee);
				break;

			case 5:
				void checkout();		
				break;

			default:
            cout << "Invalid option." << endl;
            
			} 			
	} while (option <5);
}

void checkout()
{
	if (quantity_chips > 0||quantity_milk > 0||quantity_cola > 0||quantity_coffee > 0)
	{
		total = (chips) + (milk) + (cola) + (coffee);
	
		if (total > 10)
		{ 
			cout << "Error, you are buying too much!\n";
		}
		else
		{
			cout << "Select payment option (1:Debit 2:Credit): ";
			cin >> payment;

			if (payment == 1)
			{
				void debitcard();
			}
			else if (payment == 2)
			{
				void creditcard();
			}
			else
			{
				cout << "Unknown payment option, please try again.\n";
			}
		}
	}
	else
	{
		cout << "Please select at least one item.\n";
	}
}

void debitcard()
{
	error = 1;

	cout << "Enter PIN: ";
	cin >> pin;

	if (pin == 1234)
	{
		void receipt();
	}
	else 
	{	
		while (error >= 1)
		{
			cout << "Invalid PIN. Try Again:";
			cin >> pin;
			error++;
			if (pin == 1234)
			{
				void receipt();
			}
			else
			{
				cout << "We are sorry but this is an invalid card\n"
					 << "Thank you for using us.\n"; 
				return;
			}
		}
	}
}

void creditcard()
{
	error = 1;
	
	cout << "Enter ZIP";
	cin >> zipcode;

	if (zipcode == 93955)
	{
		void receipt();
	}
	else
	{
		while (error >= 1)
		{
			cout << "Invalid ZIP. Try Again: ";
			cin >> zipcode;
			error++;
			if (zipcode == 93955)
			{
				void receipt();
			}
			else
			{
				cout << "We are sorry but this is an invalid card\n"
					 << "Thank you for using us.\n"; 
				return;
			}
		}
	}
}

void receipt ()
{
	cout << "This is your receipt:\n";

	if (quantity_chips > 0)
	{
		cout << "Sun Chips: $1.50 x " << quantity_chips << " = $" << chips << endl;
	}
	if (quantity_milk > 0)
	{
		cout << "Otter Milk: $2.00 x " << quantity_milk << " = $" << milk << endl;
	}
	if (quantity_cola > 0)
	{
		cout << "CSUMB Cola: 1.00 x " << quantity_cola << " = $" << cola << endl;
	}
	if (quantity_coffee > 0)
	{
		cout << "Regular Coffee: $2.50 x " << quantity_coffee << " = $" << coffee << endl;
	}

	tax = (total * .10);
	final_cost = tax + total;

	cout << "Tax (10.0%): $" << tax << endl;
	cout << "Total: $" << final_cost << endl;
}

int main ()
{
	menu();
	checkout();
	debitcard();
	creditcard();
	receipt();
	
	return 0;
}

Have you looked at your main() function recently?

Hey if u r coding in C++ better u can use here class and inheritance kind of which will help u to code close to c++

try using some switch case in menu and dont call directly all functions from the main

Originally Posted by rogster001

checkout() is first called from within menu()

Except, of course, it isn't. The function checkout is declared inside the menu function, but not called.

change your main function to this.

Code:

int main ()
{
	menu();
	checkout();

	
	return 0;
}

fixed
.

your checkout already calls the debit/credit, and your debit/credit already calls the receipt.