The document describes a C++ program for managing an inventory system that includes creating an index file, displaying records by ID, and handling inventory items through structure definitions. Functions are provided for adding, displaying, saving, and opening inventory data from files. The main program orchestrates these functionalities to maintain and manipulate inventory records.

1. So I already have most of the code and now I have to:
1. create an index file to keep track of all the inventory IDs and their locations
2. modify my class to be able to display any record with a given ID without searching through
the entire file
// This program displays the contents of the inventory file.
#include
#include
#include
using namespace std;
class DB{
// Declaration of InventoryItem structure
class InventoryItem
{
public:
char Id[5];
char desc[31];
int qty;
float price;
};
string DBname;
fstream inventory;// (DBname, ios::in | ios::binary);
public: DB(string N){ DBname = N; }// constructor
private:void Input(InventoryItem &Inv)
{
cout << "Please type Id" << endl;
cin >> Inv.Id;
cout << "Please type Desc" << endl;
cin >> Inv.desc;
cout << "Please type qty" << endl;
cin >> Inv.qty;
cout << "Please type price"<> Inv.price;
}
public: void Create(int Nrec)
{
inventory.open(DBname, ios::out | ios::binary);

2. // fstream inventory("Inventory.dat", ios::out | ios::binary);
InventoryItem record = { "", " ", 0, 0.0 };
// Write the blank records
for (int count = 0; count < Nrec; count++)
{
Input(record);
cout << "Now writing record " << count << endl;
inventory.write(reinterpret_cast(&record), sizeof(record));
}
// Close the file.
inventory.close();
return ;
}
public: void Display()
{
inventory.open(DBname, ios::in | ios::binary);
InventoryItem record = { "","", 0, 0.0 };
// Now read and display the records
inventory.read(reinterpret_cast(&record),
sizeof(record));
while (!inventory.eof())
{
cout << "Inventory Id: ";
cout << record.Id << endl;
cout << "Description: ";
cout << record.desc << endl;
cout << "Quantity: ";
cout << record.qty << endl;
cout << "Price: ";
cout << record.price << endl << endl;
inventory.read(reinterpret_cast(&record), sizeof(record));

3. }
// Close the file.
inventory.close();
return;
}
};
int main()
{
DB Mydb("Inventory.dat"); // declare a database
Mydb.Create(3); // load data
cout << "***** display ***" << endl;
Mydb.Display(); // print entire database
// implement the following function
// Mydb.Show("AB001"); // display record with given ID
char C; cin >> C; return 0;
}
Solution
Programming Code in C++
#include
#include
#include
#include
#include
#include
using namespace std;
//Structure.
struct InvStruct
{
string iName;
int iQuantity;
double iPrice;
};

4. const int MAXSIZE = 9;
void addToInventory(InvStruct aList[], int& aSize);
void displayInventory(const InvStruct aList[], int aSize);
void saveToFile(const InvStruct aList[], int aSize);
void openAFile(InvStruct aList[], int& aSize);
char menuResponse();
int main(int argc, char *argv[])
{
InvStruct iRecords[MAXSIZE];
int noOfRec = 0;
bool reRun = true;
do
{
cout << "Inventory has " << noOfRec << " items" << endl;
switch (menuResponse())
{
case 'A':
addToInventory(iRecords, noOfRec);
break;
case 'D':
displayInventory(iRecords, noOfRec);
break;
case 'O':
openAFile(iRecords, noOfRec);
break;
case 'S':
saveToFile(iRecords, noOfRec);
break;
case 'Q':
reRun = false;
break;
default:
cout << "Invalid Selection" << endl;

5. }
} while (reRun);
cout << endl << "Code Ends" << endl;
return EXIT_SUCCESS;
}
//Method definition addToInventory().
void addToInventory(InvStruct aList[], int& aSize)
{
InvStruct temp;
char reRun;
char iStr[256];
if (aSize < MAXSIZE)
{
system("cls");
cout << "Enter data to inventory! " << endl;
cout << "Enter data: " << endl << endl;
cout << "Name: ";
cin.getline(iStr, 256, ' ');
temp.iName = iStr;
cout << "Quantity: ";
cin >> temp.iQuantity;
cout << "Value: ";
cin >> temp.iPrice;
cout << endl;
cout << "Add more data to the inventory? (y/n) ";
cin >> reRun;
if (toupper(reRun) == 'Y')
aList[aSize++] = temp;
}
else
{
cout << "Can't add data! Inventory is full!!" << endl;
system("pause");
}
system("cls");
}

6. //Method definition displayInventory().
void displayInventory(const InvStruct aList[], int aSize)
{
system("cls");
double iCost = 0;
if (aSize < 1)
{
cout << "No data to display" << endl;
}
else
{
cout << "All data in the inventory" << endl << endl;
cout << fixed << setprecision(2);
cout << "Name Quantity Price" << endl;
cout << "--------------------------------------" << endl;
cout << left;
for (int inc = 0; inc < aSize; inc++)
{
cout << setw(21) << aList[inc].iName << right
<< setw(4) << aList[inc].iQuantity
<< setw(10) << aList[inc].iPrice << left << endl;
iCost = iCost + aList[inc].iPrice * aList[inc].iQuantity;
}
cout << "--------------------------------------" << endl;
cout << right << setw(3) << aSize;
cout << " data listed";
cout << right << setw(18) << iCost << endl << endl;
}
system("PAUSE");
system("cls");
}
//Method definition saveToFile()
void saveToFile(const InvStruct aList[], int aSize)
{
ofstream outf("Inventory.dat");
if (!outf.fail())

7. {
system("cls");
cout << "Save the inventory";
for (int inc = 0; inc < aSize; inc++)
{
outf << aList[inc].iName << ';'
<< aList[inc].iQuantity << ';'
<< aList[inc].iPrice;
if (inc < aSize - 1)
outf << endl;
}
cout << endl << aSize << " data written." << endl;
outf.close();
system("PAUSE");
system("cls");
}
else
{
cout << "Problem with the input file" << endl;
system("PAUSE");
system("cls");
}
}
void openAFile(InvStruct aList[], int& aSize)
{
ifstream inf("Inventory.txt");
string iStr;
stringstream iStrStrm;
// make sure the file stream is open before doing IO
if (!inf.fail())
{
system("cls");
cout << "Read inventory";
aSize = 0;
while (!inf.eof() && aSize < MAXSIZE)

8. {
getline(inf, iStr, ';');
aList[aSize].iName = iStr;
getline(inf, iStr, ';');
iStrStrm.str("");
iStrStrm.clear();
iStrStrm << iStr;
iStrStrm >> aList[aSize].iQuantity;
getline(inf, iStr);
iStrStrm.str(""); iStrStrm.clear();
iStrStrm << iStr;
iStrStrm >> aList[aSize++].iPrice;
}
cout << endl << aSize << " data read from the inventory." << endl;
system("PAUSE");
system("cls");
}
else
{
cout << "Problem with the input file" << endl;
system("PAUSE");
system("cls");
}
}
char menuResponse()
{
char reRun;
cout << endl << "Your selection" << endl
<< "A - Add data, D - Display data, O - Open File, S - Save File, Q - Quit" << endl
<< "> ";
cin >> reRun;
cin.ignore(256, ' ');
return toupper(reRun);
}
Sample Output:

9. Inventory has 1 item
Your selection
A- Add data, D- Display data, O - Open File, S - Save File, Q - Quit
>
D
Name Quantity Price
--------------------------------------------------------------------------------------------------
12 12.50
--------------------------------------------------------------------------------------------------
1 data listed 150.00