Thread: Storing Data into a file

I have created my own class called Account which can be used to make a saving account, deposit/ widthdraw money, etc...

First the program asks for a User ID and password. Currently, I have made it, so that one can enter anything and still continue the program.

In order to simulate a real bank, I have to create a database or something that will allow the user to create a User ID and Password and then, that information will be stored into a file of some sort. Then he/she will enter their current balance, make any transactions and 'log out.' The next time they use the program, I want to make it so that they can log in to their own account they have created earlier and continue on from there.

Right now, in my program, everytime it runs,the user must start over from the beginning.

My question is, "How can I create a database file that will store the information the user enters when he/she creates a new account?

Note that I will add the functions, "Create()" and "Destroy()" to the class later on.

Here is what the proram looks like as of now: Note that the utility library is something that i created and it contains useful functions such as GetDouble(), cls(), etc...

Code:

/*
  Name: The Bank
  Copyright: 2005
  Author: Sridar Ravi
  Date: 28/05/05 16:27
  Description: A Bank
*/

#include<iostream>
#include<conio.h>
#include<utility.h>
#include<math.h>


using namespace std;

//------------------------Prototypes and Constants------------------------------

const double Interest=0.03;
const double Natural_E=2.712;

//-----------------------User-defined Account Class-----------------------------
class Account
{
      private:  //for the private variables and methods
              double Balance;
              double Original;
              double DepositMoney;
              double WidthdrawMoney;
              
              int Years;              
              int Code;
              
              string Name;
                                    
              double InterestPay(int Years)
              {
                     double temp,temp2;
                     
                     temp=Interest*Years;
                     temp2=pow(Natural_E,temp);
                     
                     
                     return Balance*temp2;
              }
              
              
              
      public: //for public variables and methods
             Account();
             ~Account();
             
             char AskAns;
             char Ask();
             
             char Deposit_Ask;
             char DepositAns();
             
             char Widthdraw_Ask;
             char WidthdrawAns();
             
             void InputCurrentBalance();
             void Deposit();
             void Widthdraw();
             void GetBalance();
             void ListTransaction();
             void Instructions();
             void NumYears(int &Years);
             void AskName();
             void InterestAdd();
             
             
};

//-----------------Constructor and Methods and Destructor-----------------------

Account::Account() //Constructor
{       
			/*Sets everthing equal to 0*/

                  Balance=0;
                  DepositMoney=0;
                  WidthdrawMoney=0;
                  Years==0;
}

Account::~Account(){}

void Account::GetBalance()
{
     cout<<"Your balance as of now is $"<<Balance<<endl;
}

void Account::Instructions() //Postcondition:Displays intructions
{							//PreCondition: none
	cout<<"Welcome to The Bank of Sridar Ravi!\n\n";
	cout<<"This bank only allows for savings accounts at this time!\n\n";
	cout<<"Checking accounts and money market accounts will become available soon\n\n";
	cout<<"This bank allows you to enter in your initial balance\n";
	cout<<"and then you will wait for the money to grow\n\n";
	cout<<"You can also make transactions if you wish\n\n\n\n";
	cout<<"To proceed, please press ENTER now\n";
	getch();
	
	cls();
}
void Account::InputCurrentBalance() //Postcondition:entering current balance
{									//Precondition: Nothing
     
     cout<<"Enter the current balance on your account now in dollars: $";
     cin>>Balance;
     Original=Balance;
     
}

void Account::Deposit() //Postcondition:Method for depositing money
{						//Precondition: Nothing Any $ amount can be put in
     cout<<"How much do you want to deposit into your account?: $";
     DepositMoney=GetDouble(0,1000000000); // for illegal transactions
     Balance+=DepositMoney;
     //Balance+=InterestPay(Years); //pays interest
     cout<<"The new balance with the interest added now is: $"<<Balance<<endl;
     
}

void Account::Widthdraw() //Postcondition:Method for taking money from bank
						//PreCondition: Money can't be more than balance
						
{
     cout<<"How much would you like to widthdraw?: $";
     WidthdrawMoney=GetDouble(0,Balance);
     Balance-=WidthdrawMoney;
     cout<<"Please wait while we process you new balance...\n";
     Wait(2500);
}


void Account::ListTransaction()  //Postcondition:Prints the transaction
{								//PreCondition: Nothing
	cout<<"\n\n";
	cout<<"Your Transaction\n\n";
	cout<<"Your original balance was: $"<<Original<<"\n";
	cout<<"You deposited: $"<<DepositMoney<<endl;
	cout<<"You widthdrew: $"<<WidthdrawMoney<<endl;
	cout<<"The new balance is: $"<<Balance<<endl;
	cout<<"This bank gives you an interst rate of "<<Interest*100<<"% compounded continuously\n";
	cout<<"We hope you are content with the transaction!\n";
	}

char Account::Ask()  //Postcondition:Asks if program should run again
{					//No Precondition
	cout<<"What would you like to do now? \n";
	cout<<"A---------Another Transaction\n";
	cout<<"N---------New User\n";
	cout<<"Q---------Quit\n";
	cout<<"Please enter one of the choices: ";
    cin>>AskAns;	
	return AskAns;	
}

void Account::NumYears(int &Years)
{
     cout<<"How many years has passed since the last transaction or starting this account?: ";
     cin>>Years;     
}

void Account::AskName()
{
     
     cout<<"Please enter in your User ID: ";
     cin>>Name;
     cout<<"Enter your 5 digit access number provided by Sridar: ";
     cin>>Code;
     cout<<"Thank You!\n";
     cout<<"Press ENTER to proceed\n";
     getch();
     cls();
}

void Account::InterestAdd()
{
     NumYears(Years);
     Balance=InterestPay(Years); //pays interest
     cout<<"The new balance with the interest added now is: $"<<Balance<<endl;
}

char Account::WidthdrawAns()
{
     cout<<"Would you like to widthdraw?: ";
     cin>>Widthdraw_Ask;
     return Widthdraw_Ask;
}
 
char Account::DepositAns()
{
     cout<<"Would you like to deposit?: ";
     cin>>Deposit_Ask;
     return Deposit_Ask;
}


//-------------------------------------Main--------------------------------
int main()
{
	
	cout.setf(ios::fixed); cout.precision(2); //Rounds everything to 2 decimal  places
	
 newuser:
	
    Account X; //creating an instance of the class	
	X.Instructions();
	X.AskName();    
    
        	
    Account Sridar;//main instance of Account class    
    
    Sridar.InputCurrentBalance();
    
 start:
    
    int years;
    char Answer;
    
    Sridar.InterestAdd();    
    
    if(Sridar.DepositAns()=='y')
    {
                                Sridar.Deposit();
                                }
    if(Sridar.WidthdrawAns()=='y')
    {
                                Sridar.Widthdraw();
                                }
    
    
    Sridar.ListTransaction();
                                  
    Answer=Sridar.Ask();
   
    if(Answer=='Q')
    {
    	cout<<"Have a nice day!\n";
    	getch();
    	cls();
    }
    
    if(Answer=='A')
    {
    	cout<<"Okay! Press Enter now\n";
    	getch();
    	cls();
    	goto start;
    }
    
    if(Answer=='N')
    {
         cout<<"Logging Out...";
         Wait(2000);
         cls();
         goto newuser;
         }
    
    return 0;
}

Please Help ME!

Yes, and once you have learned the mechanics of file i/o, you'll wonder how you're going to store the information. By the looks of your program, the simplest way would just to have the program save information in a definite order, line by line. Of course, in the case of multiple accounts, things could get stickier. Most extravagantly, you could look into an XML parser/coder.