Running an inventory program. When adding an item and after input of date, the program loops. The output shows the error message for quantity input less than 1.

/***************************************************

This program demonstrates an inventory allowing user

to add, edit, and display records in a file.

***************************************************/

#include

#include

using namespace std;

const int DESCRIPTION = 20;

// Function prototype

void Add();

void Display();

void Edit();

// Structure definition

struct Inventory

{

char item[DESCRIPTION];

int qty;

double wholeCost;

double retailCost;

char date[10];

};

int main()

{

// Variables

int select;

do

{

// Menu

cout << "MENU" << endl;

cout << "1. Add Record" << endl;

cout << "2. Display Record" << endl;

cout << "3. Edit Record" << endl;

cout << "4. Exit" << endl;

cout << "Enter your selection: ";

cin >> select;

cout << endl;

switch (select)

{

case 1:

Add();

break;

case 2:

Display();

break;

case 3:

Edit();

break;

case 4:

break;

default:

cout << "Invalid entry" << endl;

break;

}

} while (select != 4);

system("pause");

return 0;

}

// Function Add

void Add()

{

fstream fout;

const int size = 3;

char ch;

fout.open("Records.txt", ios::out);

Inventory inv;

do

{

cout << "Enter the item description: ";

cin.ignore();

cin.getline(inv.item, DESCRIPTION);

cout << "Enter the quantity: ";

cin >> inv.qty;

while (inv.qty < 1)

{

cout << "Quantity must be 1 or more." << endl << endl;

cout << "Enter the quantity: ";

cin >> inv.qty;

}

cout << "Enter the wholesale cost: ";

cin >> inv.wholeCost;

while (inv.wholeCost <= 0)

{

cout << "Cost must be greater than 0." << endl << endl;

cout << "Enter the wholesale cost: ";

cin >> inv.wholeCost;

}

cout << "Enter the retail cost: ";

cin >> inv.retailCost;

while (inv.retailCost <= 0)

{

cout << "Cost must be greater than 0." << endl << endl;

cout << "Enter the retail cost: ";

cin >> inv.retailCost;

}

cout << "Enter the date as mm-dd-yyyy: ";

cin.ignore();

cin.getline(inv.date, 10);

fout.write(reinterpret_cast(&inv), sizeof(inv));

cout << "Enter another record?" << endl;

cout << "Enter Y for yes: ";

cin >> ch;

cout << endl;

} while (ch == 'Y' || ch == 'y');

fout.close();

}

// Function Display

void Display()

{

fstream fout;

fout.open("Records.txt", ios::in);

Inventory inv;

fout.read(reinterpret_cast(&inv), sizeof(inv));

while (!fout.eof())

{

cout << " Description\t";

cout << inv.item;

cout << " Quantity\t";

cout << inv.qty;

cout << " Wholesale cost\t";

cout << inv.wholeCost;

cout << " Retail cost\t";

cout << inv.retailCost;

cout << " Date\t";

cout << inv.date;

cout << endl;

fout.read(reinterpret_cast(&inv), sizeof(inv));

}

fout.close();

cout << endl;

}

// Function Edit

void Edit()

{

fstream fout;

fout.open("Records.txt", ios::in | ios::out);

Inventory inv;

int recordNum;

cout << "Enter the record number to edit: ";

cin >> recordNum;

recordNum -= 1;

fout.seekg(recordNum * sizeof(inv), ios::beg);

fout.read(reinterpret_cast(&inv), sizeof(inv));

cout << " Description\t";

cout << inv.item;

cout << " Quantity\t";

cout << inv.qty;

cout << " Wholesale cost\t";

cout << inv.wholeCost;

cout << " Retail cost\t";

cout << inv.retailCost;

cout << " Date\t";

cout << inv.date;

cout << endl << endl;

cout << "Enter the new description: ";

cin.ignore();

cin.getline(inv.item, DESCRIPTION);

cout << "Enter the quantity: ";

cin >> inv.qty;

while (inv.qty < 1)

{

cout << "Quantity must be 1 or more." << endl << endl;

cout << "Enter the quantity: ";

cin >> inv.qty;

}

cout << "Enter the wholesale cost: ";

cin >> inv.wholeCost;

while (inv.wholeCost <= 0)

{

cout << "Cost must be greater than 0." << endl << endl;

cout << "Enter the wholesale cost: ";

cin >> inv.wholeCost;

}

cout << "Enter the retail cost: ";

cin >> inv.retailCost;

while (inv.retailCost <= 0)

{

cout << "Cost must be greater than 0." << endl << endl;

cout << "Enter the retail cost: ";

cin >> inv.retailCost;

}

cout << "Enter the date: ";

cin.ignore();

cin.getline(inv.date, 10);

cout << endl;

// Move back to the beginning of this record's position

fout.seekg(recordNum * sizeof(inv), ios::beg);

// Write new record over the current record

fout.write(reinterpret_cast(&inv), sizeof(inv));

fout.close();

}