C++ for Dummies (3rd Edition)/C_FD.iso/CHAP26/BUDGET6.CPP

C/C++ Source or Header | 1996-09-02 | 6KB | 254 lines

//BUDGET6.CPP - Budget program using a template container
//              class to hold the account objects rather
//              than embed that information into the class.

#include <iostream.h>
#include <stdlib.h>
#include <ctype.h>

// use the template class SLL
#include "sll.h"

//Account - this abstract class incorporates properties
//          common to both account types Checking and
//          Savings; however, it's missing the concept
//          withdrawal() which is different between the two
class Account
{
  protected:
    Account(Account &c)
    {
        throw "No creating funds\n";
    }

  public:
    Account(unsigned accNo, float initialBalance = 0.0F);

    //access functions
    int accountNo()
    {
        return accountNumber;
    }
    float acntBalance()
    {
        return balance;
    }

    //transaction functions
    void deposit(float amount)
    {
        balance += amount;
    }
    virtual void withdrawal(float amount) = 0;

    //display function for displaying self on 'cout'
    void display()
    {
        cout << "Account " << accountNumber
             << " = "      << balance
             << "\n";
     }

  protected:
    unsigned   accountNumber;
    float      balance;
};

Account::Account(unsigned accNo, float initialBalance)
{
    accountNumber = accNo;
    balance = initialBalance;
}

//Checking - this class contains properties unique to
//           checking accounts.  Not much left is there?
class Checking : public Account
{
  public:
    //here the constructor defined inline
    Checking(unsigned accNo, float initialBalance = 0.0F) :
             Account(accNo, initialBalance)
    {
    }

    //overload pure virtual functions
    virtual void withdrawal(float amount);
};

void Checking::withdrawal(float amount)
{
    if (balance < amount )
    {
        cout << "Insufficient funds: balance " << balance
             << ", check "                     << amount
             << "\n";
    }
    else
    {
        balance -= amount;

        //if balance falls too low, charge service fee
        if (balance < 500.00F)
        {
            balance -= 0.20F;
        }
    }
}


//Savings - same story as Checking except that it also
//          has a unique data member
class Savings : public Account
{
  public:
    //here constructor defined as separate function
    //just to show you the difference
    Savings(unsigned accNo, float initialBalance = 0.0F);

    //transaction functions
    virtual void withdrawal(float amount);


  protected:
    int noWithdrawals;
};

Savings::Savings(unsigned accNo, float initialBalance) :
   Account(accNo, initialBalance)
{
    noWithdrawals = 0;
}
void Savings::withdrawal(float amount)
{
    if (balance < amount)
    {
        cout << "Insufficient funds: balance " << balance
             << ", withdrawal "                << amount
             << "\n";
    }
    else
    {
        if (++noWithdrawals > 1)
        {
            balance -= 5.00F;
        }
        balance -= amount;
    }
}

//prototype declarations
unsigned getAccntNo();
void process(Account &account);

//main - accumulate the initial input and output totals
int main()
{
    // loop until someone enters an 'X' or 'x'
    Account *pA;
    char     accountType;     //S or C

    try
    {
        // keep the accounts in an account container
        SLL<Account> books;                       // Note 1

        unsigned keepLooping = 1;
        while (keepLooping)
        {
            cout << "Enter S for Savings, "
                    "C for Checking, X for exit\n";
            cin  >> accountType;

            switch (accountType)
            {
              case 'c':
              case 'C':
                pA = new Checking(getAccntNo());
                if (pA == 0)
                {
                    throw "Out of memory";
                }
                process(*pA);
                books.add(pA);                   // Note 2
                break;

              case 's':
              case 'S':
                pA = new Savings(getAccntNo());
                if (pA == 0)
                {
                     throw "Out of memory";
                }
                process(*pA);                    // Note 2
                books.add(pA);
                break;

              case 'x':
              case 'X':
                keepLooping = 0;
                break;

             default:
                cout << "I didn't get that.\n";
           }
        }

        //now present totals
        float total = 0.0;
        cout << "Account totals:\n";
                                                     // Note 3
        for (books.reset(); pA = books.current(); books.over())
        {
            pA->display();
            total += pA->acntBalance();
        }
        cout << "Total worth  = " << total << "\n";
    }

    // char* exception is a general, internal error
    catch(char* pReason)                               // Note 4
    {
        cout << "Exception: " << pReason << endl;
    }
    catch(...)
    {
        cout << "Unknown exception\n" << endl;
    }
    return 0;
}

//getAccntNo - return the account number entered
unsigned getAccntNo()
{
    unsigned accntNo;
    cout << "Enter account number:";
    cin  >> accntNo;
    return accntNo;
}

//process(Account) - input the data for an account*/
void process(Account &account)
{
    cout << "Enter positive number for deposit,\n"
            "negative for withdrawal, 0 to terminate";

    float transaction;
    do
    {
        cout << ":";
        cin  >> transaction;

        //deposit
        if (transaction > 0.0F)
        {
            account.deposit(transaction);
        }

        //withdrawal
        if (transaction < 0.0F)
        {
            account.withdrawal(-transaction);
        }
    } while (transaction != 0.0F);
}