Chapter 1, Problem 16R

Explanation of Solution

Program code:

main.cpp

//include the requird header files

#include <vector>

#include "CreditCard.h"

//use the namespace

using namespace std;

//define the function textCard()

void testCard()

{

    // vector of CC pointers

    vector <CreditCard*> wallet(10);

    //create the credit card details

    wallet[0] = new CreditCard(5391037593875309,"JoBlo",2500);

    wallet[1] = new CreditCard(3485039933951954,"JoBlo",3500);

    wallet[2] = new CreditCard(6011490232942994,"JoBlo",5000);

    //iterate a for loop

    for (int i = 0; i < 3; i++)

    {

        //iterate a for loop

        for (int j = 1; j <= 16; j++)

        {

            // explicit cast

            wallet[0] -> chargeIt(double(i));

            // implicit cast

            wallet[1] -> chargeIt(2.0 * i);

            wallet[1] -> chargeIt(2.0 * i);

        }

        //print the card details

           cout << *wallet[i];

        //iterate a while loop to get the balance

        while (wallet[i]->getBalance() > 100.0)

        {

            //call the method makePayment

            wallet[i]->makePayment(100.0);

            //print the new balance

            cout << "New balance = " <<

            wallet[i]->getBalance() << "\n";

        }

        //deleting a walllet

        delete wallet[i];

    }

}

//define the main() method

int main()

{

    //First test case

    CreditCard CC = CreditCard(1234, "Bill gates", 2500);

    CC.chargeIt(1000);

    CC.chargeIt(-100);

    CC.chargeIt(500);

    CC.makePayment(-100);

    CC.makePayment(300);

    cout << CC << endl << endl;

    //given test case

    testCard();

    return EXIT_SUCCESS;

}

Explanation:

In the code,

• Include the required header files.
• Use the namespace.
• Define the “testCard()” method.
  • Create vector pointers
  • Create array “wallet[]” to store credit card details.
  • Iterate a “for” loop.
    • Iterate a “for” loop.
      • Explicit cast.
      • Implicit cast.
    • Print the card details.
    • Iterate a “while” loop to get the balance.
      • Call the method “makepayment()”.
      • Print the new balance.
    • Delete a wallet.
• Define the “main()” function.
  • Enter the credit card details.
  • Call the function “chargeIt()” and “makePayment()” using “CC”.
  • Call the function “testCard()”.
  • Return “EXIT_SUCCESS”.

CreditCard.cpp

//Code for CreditCard.cpp

#include "CreditCard.h"

using namespace std;

//define the constructor CreditCard

CreditCard::CreditCard(long long int no, const string& nm, int lim, double bal)

{

    //declare the required variables

    number = no;

    name = nm;

    limit = lim;

    balance = bal;

}

//define a function chargeIt()

bool CreditCard::chargeIt(double price)

{

    if(price <= 0)

    {

        //print error message when price is negative

        cout << "Error: Input argument must be positive.\n";

        //return false

        return false;

    }

    //if the condition is true

    if (price + balance > double(limit))

    {

        //return false

        return false;

    }

    //add price to balance

    balance += price;

    //update fraction

    fraction = double(balance)*100.0/limit;

    //if the condition is true

    if(fraction > FRACTION_LIMIT)

    {

//print warning message when fraction is more than 50%

printf("Warning: the current balance on credit card %lld is %.2f%c of your limit.\n", number, fraction, '%');

    }

    // the charge goes through

    return true;

}

//define the function makePayment

void CreditCard::makePayment(double amount)

{

    //create a variable

    const double interestRate = 0.10;

    //if amount less than or equal to 0

    if(amount <= 0)

    {

        //return

        return;

    }

    //set the value of balance

    balance -= amount * (1 + interestRate);

}

ostream& operator<<(ostream& out, const CreditCard& c)

{

    //print method

    out << "Number = " << c.getNumber() << "\n"

    << "Name = " << c.getName() << "\n"

    << "Balance = " << c.getBalance() << "\n"

    << "Limit = " << c.getLimit() << "\n";

    return out;

}

Explanation:

In the code,

• Include the required header files.
• Use the namespace.
• Define the constructor “creditCard()”.
  • Declare the required variables.
• Define the function “chargeIt()”.
  • If the value of the “price” is less than or equal to 0.
    • Print an error message that the price must be positive.
    • Return a value “false”.
      • If the condition is true,
        • Return false.
      • Add the value of “price” to “balance”.
      • Update the value of “fraction”.
      • If the condition “fraction > FRACTION_LIMIT” is true.
        • Print a warning message.
      • Return true.
• Define the function “makePayment()”.
  • Create a variable “interestrate”.
  • If the value of the “amount” is less than or equal to 0.
    • Return.
      • Set the value of “balance”.
• Print the details.
  • Enter the credit card details.
  • Call the function “getNumber()” and “getName()”,“getBalance()” ,and “getLimit()”.
  • Call the function “testCard()”.
  • Return “out”.

CreditCard.h

//Code for CreditCard.h:

#ifndef CreditCard_H

#define CreditCard_H

#include<iostream>

//interest rate

#define INTEREST 5

//fraction limit

#define FRACTION_LIMIT 50.00

//define a class

class CreditCard

{

    //public access specifier

    public:

        //class member functions

        CreditCard(long long int no, const std::string& nm,

        int lim, double bal = 0);

        long long int getNumber() const

        {

            return number;

        }

        std::string getName() const

        {

            return name;

        }

        double getBalance() const

        {

            return balance;

        }

        int getLimit() const

        {

        return limit;

}

// make a charge

bool chargeIt(double price);

// make a payment

void makePayment(double amount);

//private access specifier

private:

//class members

// credit card number

long long int number;

// card owner's name

std::string name;

// the current balance

double balance;

// the credit limit

int limit;

//maintains the fraction

double fraction;

};

// print card information

std::ostream& operator<<(std::ostream& out, const CreditCard& c);

#endif

Explanation:

In the code,

• Include the required header files...