Chapter 10, Problem 1P

Solution to Practice Program 10.1

Redefine CDAccount from Display 10.1 so that it is a class rather than a structure. Use the same member variables as in Display 10.1 but make them private. Include member functions for each of the following: one to return the initial balance, one to return the balance at maturity, one to return the interest rate, and one to return the term. Include a constructor that sets all of the member variables to any specified values, as well as a default constructor. Embed your class definition in a test program.

Program Plan Intro

Redefine CDAccount

Program Plan:

• Include the necessary libraries.
• Use namespace.
• Define a class.
  • Declare the member functions as public.
  • Declare the variables as private.
• Define the main method.
  • Declare the variables that are required for the program.
  • Call the function.
  • Display the messages.
• Add member functions
  • Default constructor.
  • Constructor to set specified values.
  • To return interest rate.
  • To return initial balance.
  • To return balance at maturity.
  • To return the term.
  • input function (istream&);
  • output function (ostream&);

Program Description Answer

Program Description:

The following C++ program redefines CDAccount from Display 10.1 to be a class rather than struct.

Explanation of Solution

Program:

//Include libraries

#include <iostream>

//Use namespace

using namespace std;

//Define class

class CDAccount

{

//Public specifiers

public:

    //Declare member functions

    CDAccount();

    CDAccount(double bal, double intRate, int T);

    double InterestRate();

    double InitialBalance();

    double BalanceAtMaturity();

    int Term();

    void input(istream&);

    void output(ostream&);

//Private specifiers

private:

    //Declare variables

    double balance;

    double interestRate; // in PER CENT

    int term; // months to maturity;

};

//Main function

int main()

{

    //Declare variables

    double balance; double intRate;

    int term;

    //Constructor

    CDAccount account = CDAccount(100.0, 10.0, 6);

    //Display message

    cout << "CD Account interest rate: "

        << account.InterestRate() << endl;

    //Display message

    cout << "CD Account initial balance: "

        << account.InitialBalance() << endl;

    //Display message

    cout << "CD Account balance at maturity is: "

        << account.BalanceAtMaturity() << endl;

    //Display message

    cout << "CD Account term is: " << account.Term()

        << " months" << endl;

    account.output(cout);

    //Display message

    cout << "Enter CD initial balance, interest rate, "

        << " and term: " << endl;

    account.input(cin);

    //Display message

    cout << "CD Account interest rate: "

        << account.InterestRate() << endl;

    //Display message

    cout << "CD Account initial balance: "

        << account.InitialBalance() << endl;

    //Display message

    cout << "CD Account balance at maturity is: "

        << account.BalanceAtMaturity() << endl;

    //Display message

    cout << "CD Account term is: " << account.Term()

        << " months" << endl;

    account.output(cout);

    //Newline character

    cout << endl;

    //Pause console window

    system("pause");

}

//Default constructor

CDAccount::CDAccount() { /* do nothing */ }

//Constructor to set specified values

CDAccount::CDAccount(double bal, double intRate, int T)

{

    balance = bal;

    interestRate = intRate;

    term = T;

}

//Function to return interest rate

double CDAccount::InterestRate()

{

    //Return value

    return interestRate;

}

//Function to return initial balance

double CDAccount::InitialBalance()

{

    //Return value

    return balance;

}

//Function to return the balance at maturity

double CDAccount::BalanceAtMaturity()

{

    //Return value

    return balance * (1 + (interestRate / 100)*(term / 12.0));

}

//Function to return the term

int CDAccount::Term()

{

    //Return value

    return term;

}

//Input Function

void CDAccount::input(istream& inStream)

{

    //Store value

    inStream >> balance;

    inStream >> interestRate;

    inStream >> term;

}

//Output function

void CDAccount::output(ostream& outStream)

{

    //Display values

    outStream.setf(ios::fixed);

    outStream.setf(ios::showpoint);

    outStream.precision(2);

    //Display message

    outStream << "when your CD matures in " << term

        << " months" << endl

        << "it will have a balance of "

        << BalanceAtMaturity() << endl;

}

Sample Output

Output:

CD Account interest rate: 10

CD Account initial balance: 100

CD Account balance at maturity is: 105

CD Account term is: 6 months

when your CD matures in 6 months

it will have a balance of 105.00

Enter CD initial balance, interest rate, and term:

100

10

12

CD Account interest rate: 10.00

CD Account initial balance: 100.00

CD Account balance at maturity is: 110.00

CD Account term is: 12 months

when your CD matures in 12 months

it will have a balance of 110.00

Press any key to continue . . .