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//DISPLAY 10.7 Alternative BankAccount Class Implementation
//Demonstrates an alternative implementation of the class BankAccount.
#include <iostream>
#include <cmath>
using namespace std;
//Class for a bank account:
class BankAccount
{
public:
BankAccount(int dollars, int cents, double rate);
//Initializes the account balance to $dollars.cents and
//initializes the interest rate to rate percent.
BankAccount(int dollars, double rate);
//Initializes the account balance to $dollars.00 and
//initializes the interest rate to rate percent.
BankAccount( );
//Initializes the account balance to $0.00 and the interest rate to 0.0%.
void update( );
//Postcondition: One year of simple interest has been added to the account
//balance.
double get_balance( );
//Returns the current account balance.
double get_rate( );
//Returns the current account interest rate as a percentage.
void output(ostream& outs);
//Precondition: If outs is a file output stream, then
//outs has already been connected to a file.
//Postcondition: Account balance and interest rate
//have been written to the stream outs.
private:
int dollars_part;
int cents_part;
double interest_rate;//expressed as a fraction, for example, 0.057 for 5.7%
double fraction(double percent);
//Converts a percentage to a fraction. For example, fraction(50.3)
//returns 0.503.
double percent(double fraction_value);
//Converts a fraction to a percentage. For example, percent(0.503)
//returns 50.3.
};
int main( )
{
BankAccount account1(100, 2.3), account2;
cout << "account1 initialized as follows:\n";
account1.output(cout);
cout << "account2 initialized as follows:\n";
account2.output(cout);
account1 = BankAccount(999, 99, 5.5);
cout << "account1 reset to the following:\n";
account1.output(cout);
return 0;
}
BankAccount::BankAccount(int dollars, int cents, double rate)
{
if ((dollars < 0) || (cents < 0) || (rate < 0))
{
cout << "Illegal values for money or interest rate.\n";
exit(1);
}
dollars_part = dollars;
cents_part = cents;
interest_rate = fraction(rate);
}
BankAccount::BankAccount(int dollars, double rate)
{
if ((dollars < 0) || (rate < 0))
{
cout << "Illegal values for money or interest rate.\n";
exit(1);
}
dollars_part = dollars;
cents_part = 0;
interest_rate = fraction(rate);
}
BankAccount::BankAccount( ) : dollars_part(0), cents_part(0), interest_rate(0.0)
{
//Body intentionally empty.
}
double BankAccount::fraction(double percent_value)
{
return (percent_value/100.0);
}
//Uses cmath:
void BankAccount::update( )
{
double balance = get_balance( );
balance = balance + interest_rate*balance;
dollars_part = floor(balance);
cents_part = floor((balance - dollars_part)*100);
}
double BankAccount::get_balance( )
{
return (dollars_part + 0.01*cents_part);
}
double BankAccount::percent(double fraction_value)
{
return (fraction_value*100);
}
double BankAccount::get_rate( )
{
return percent(interest_rate);
}
//Uses iostream:
void BankAccount::output(ostream& outs)
{
outs.setf(ios::fixed);
outs.setf(ios::showpoint);
outs.precision(2);
outs << "Account balance $" << get_balance( ) << endl;
outs << "Interest rate " << get_rate( ) << "%" << endl;
}
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