How float values stored in file??

[Rupali12345]

hi all,

In following code itemdescription value is stored properly in file but the float values are stored as different symbols such as @,@A etc.
If i want to store float values also as it is...what should I do??

 
 
#include <iostream>
#include <conio.h>
#include <fstream>
#include <string>
using namespace std;
 
class Inventory
{
private:
    char ItemDescription[6];
    float Stock;        
    float Quantity;
    float Price;
public:
     void DataEntry();
 
};
 
void Inventory::DataEntry()
{
    char desc[6];
    float inNum;
 
    cout<<"PLEASE ENTER A ITEM DESCRIPTION: ";
    cin.getline(desc,10);
    strcpy(ItemDescription , desc);
 
    cout<<endl<<"ENTER THE STOCK NUMBER OF ITEM: ";
    cin>>inNum;
    if (inNum<0||inNum>999)
    {
        throw ("** Invalid Stock Number **");
        return;
    }
    else
    {   
         //::_itoa((int)inNum,(char *)Stock,10);
        Stock=inNum;
    }
 
    cin.get();
    cout<<"ENTER HOW MANY ITEMS ARE: ";
    cin>>inNum;
    if (inNum<0)
    {
      throw ("** Invalid quantity **"); 
      return; 
    } 
    else
    {    
        Quantity=inNum;
    }
    cin.get();
    cout<<"ENTER THE PRICE OF ITEM: ";
    cin>>inNum;
    if (inNum<0||inNum>500)
    {
        throw ("** Invalid Price **"); 
        return; 
    } 
    else
    {   
        Price=inNum;
    }
    cin.get();
    return; 
}
 
int main()
{
    Inventory Num;
    const int numItem=3;
    try
    {
        Num.DataEntry();
    }
    catch(const char msg[])
    {
        cout<<"***************************"<<endl;
        cout<<"\n********FATAL ERROR********"<<endl;
        cout<<"Error: "<<msg<<endl;
        cin.get();
        cin.get();
        return 0;
    }
    Inventory Item[numItem];
    ofstream dataFile("itemInventory.txt");
    for(int x=1;x<numItem;x++)
    {
        try 
        {
               Item[x].DataEntry();
        } 
 
        catch (const char msg[])
        {
            cout << "Error: " << msg <<endl;
        }
 
        dataFile.write(( char*)(&Item[x]),sizeof(Item[x]));
    }
 
    cout<<"DATA ENTRY COMPLETE."<<endl;
 
    cin.get();
    return 0;
}
 

[weaknessforcats]

Your code has some bugs in it.
1) the DataEntry function does a getline of 10 into an array of 6. Crashes here.
2) your file write does a really ugly C-style cast where you lie to the compiler by telling it the address of an Inventory object is a char*. Big no-no.

I added an inserter (operator<<) to your code to avoid the cast and fixed the getline of 10.

The fixed code is below and the output file has your expected data.

I didn't check for validity.

#include <iostream>
#include <conio.h>
#include <fstream>
#include <string>
using namespace std;
 
class Inventory
{
private:
    char ItemDescription[6];
    float Stock;        
    float Quantity;
    float Price;
public:
     void DataEntry();
     friend ostream& operator<<(ostream& os, const Inventory& rhs);
 
};
ostream& operator<<(ostream& os, const Inventory& rhs)
{
   os << rhs.ItemDescription << " " << rhs.Price << " "
        << rhs.Quantity << " " << rhs.Stock << endl;
   return os;
}
void Inventory::DataEntry()
{
    char desc[6];
    float inNum;
 
    cout<<"PLEASE ENTER A ITEM DESCRIPTION: ";
    //cin.getline(desc,10);
    cin.getline(desc,6);
    strcpy(ItemDescription , desc);
 
    cout<<endl<<"ENTER THE STOCK NUMBER OF ITEM: ";
    cin>>inNum;
    if (inNum<0||inNum>999)
    {
        throw ("** Invalid Stock Number **");
        return;
    }
    else
    {   
         //::_itoa((int)inNum,(char *)Stock,10);
        Stock=inNum;
    }
 
    cin.get();
    cout<<"ENTER HOW MANY ITEMS ARE: ";
    cin>>inNum;
    if (inNum<0)
    {
      throw ("** Invalid quantity **"); 
      return; 
    } 
    else
    {    
        Quantity=inNum;
    }
    cin.get();
    cout<<"ENTER THE PRICE OF ITEM: ";
    cin>>inNum;
    if (inNum<0||inNum>500)
    {
        throw ("** Invalid Price **"); 
        return; 
    } 
    else
    {   
        Price=inNum;
    }
    cin.get();
    return; 
}
 
int main()
{
    Inventory Num;
    const int numItem=3;
    try
    {
        Num.DataEntry();
    }
    catch(const char msg[])
    {
        cout<<"***************************"<<endl;
        cout<<"\n********FATAL ERROR********"<<endl;
        cout<<"Error: "<<msg<<endl;
        cin.get();
        cin.get();
        return 0;
    }
    Inventory Item[numItem];
   // ofstream dataFile("itemInventory.txt");
    ofstream dataFile("c:\\scratch\\instructor\\itemInventory.txt");
    for(int x=1;x<numItem;x++)
    {
        try 
        {
            Item[x].DataEntry();
        } 
 
        catch (const char msg[])
        {
            cout << "Error: " << msg <<endl;
        }
 
        dataFile << Item[x];
        //dataFile.write(( char*)(&Item[x]),sizeof(Item[x]));
    }
 
    cout<<"DATA ENTRY COMPLETE."<<endl;
 
    cin.get();
    return 0;
}
 

[Rupali12345]

Thanks,
It's working fine now...I learn many things from this example...