Exercise 11.4 (Completed)

1. (Modify) a. Replace the operator[] function in Program 11.9 with the operator() function.

Done!!

b. Include the operator() function written for Exercise 1a in a working C++ program and
verify its operation.

//Same result as the operator[].
#include "stdafx.h" 
#include <iostream>
#include <iomanip>
using namespace std;
// class declaration section
class Date
{
private:
	int month;
	int day;
	int year;
public:
	Date(int = 7, int = 4, int = 2012);    // constructor
	Date operator()(int);   // function prototype
	void showDate();        // member function to display a Date
};
// class implementation section
Date::Date(int mm, int dd, int yyyy)
{
	month = mm;
	day = dd;
	year = yyyy;
}
Date Date::operator()(int days)
{
	Date temp;    // a temporary Date to store the result
	temp.day = day + days;    // add the days
	temp.month = month;
	temp.year = year;
	while (temp.day > 30)     // now adjust the months
	{
		temp.month++;
		temp.day -= 30;
	}
	while (temp.month > 12)   // adjust the years
	{
		temp.year++;
		temp.month -= 12;
	}
	return temp;    // the values in temp are returned
}
void Date::showDate()
{
	cout << setfill('0')
		<< setw(2) << month << '/'
		<< setw(2) << day << '/'
		<< setw(2) << year % 100;
	return;
}
int main()
{
	Date oldDate(7, 4, 2011), newDate; // declare two objects
	cout << "The initial Date is ";
	oldDate.showDate();
	newDate = oldDate(284); // add in 284 days = 9 months and 14 days
	cout << "\nThe new Date is ";
	newDate.showDate();
	cout << endl;
	system("PAUSE");
	return 0;
}

2. (Modify) a. Replace the operator[] function in Program 11.9 with a member operator()
function that accepts an integer month, day, and year count. Have the function add the input
days, months, and years to the object’s date and return the resulting date. For example, if the
input is 3, 2, 1 and the object’s date is 7/16/2011, the function should return the date 10/18/2012.
Make sure your function correctly handles an input such as 37 days and 15 months and adjusts
the calculated day to be within the range 1 to 30 and the month to be within the range 1 to 12.
Therefore, if the input is 37, 15, 1 and the object’s date is 7/16/2011, the function should return
the date 9/1/2015.

Done!!

b. Include the operator() function written for Exercise 2a in a working C++ program and
verify its operation.

#include "stdafx.h" 
#include <iostream>
#include <iomanip>
using namespace std;
// class declaration section
class Date
{
private:
	int month;
	int day;
	int year;
public:
	Date(int = 7, int = 4, int = 2012);    // constructor
	Date operator()(int ,int, int);   // function prototype
	void showDate();        // member function to display a Date
};
// class implementation section
Date::Date(int mm, int dd, int yyyy)
{
	month = mm;
	day = dd;
	year = yyyy;
}
Date Date::operator()(int months, int days, int years)
{
	Date temp;    // a temporary Date to store the result
	temp.day = day + days;    // add the days
	temp.month = month + months;
	temp.year = year + years;
	while (temp.day > 30)     // now adjust the months
	{
		temp.month++;
		temp.day -= 30;
	}
	while (temp.month > 12)   // adjust the years
	{
		temp.year++;
		temp.month -= 12;
	}
	return temp;    // the values in temp are returned
}
void Date::showDate()
{
	cout << setfill('0')
		<< setw(2) << month << '/'
		<< setw(2) << day << '/'
		<< setw(2) << year % 100;
	return;
}
int main()
{
	Date oldDate(7, 16, 2011), newDate; // declare two objects
	cout << "The initial Date is ";
	oldDate.showDate();
	newDate = oldDate(37, 15 ,1); // add in 284 days = 9 months and 14 days
	cout << "\nThe new Date is ";
	newDate.showDate();
	cout << endl;
	system("PAUSE");
	return 0;
}

3. (Program) a. Construct a class named Student consisting of these private data members: an
integer ID number, an integer count, and an array of four double-precision grades. The constructor
for this class should set all data member values to 0. The class should also include a
member function that displays all valid member grades, as determined by the grade count, and
calculates and displays the average of the grades. Include the class in a working C++ program
that declares three class objects named a, b, and c.

#include "stdafx.h" 
#include <iostream>
#include <iomanip>
using namespace std;
// class declaration section
class Student
{
private:
	int IDnum;
	int count;
	double arr[4];
public:
	Student(int = 0, int = 0, double = 0);    // constructor
	Student operator()(int);   // function prototype
	void showStudent();        // member function to display a Student
};
// class implementation section
Student::Student(int ii, int cc, double aa)
{
	IDnum = ii;
	count = cc;
	arr[count]= aa;

}

void Student::showStudent()
{
	for (count = 1; count < 4; count++) {
		IDnum = count * rand() %1000;
		arr[count] = rand() % 100 + 70;
	}
	double ans = ((arr[0] + arr[1] + arr[2] + arr[3]) / 4);
	cout <<"The student with ID number " << IDnum << " Average is " << ans << endl;
	return;
}
int main()
{
	Student a,b,c; // declare two objects
	cout << "The Student's info is "<< endl;
	a.showStudent();
	b.showStudent();
	c.showStudent();
	system("PAUSE");
	return 0;
}

b. Modify the class constructed for Exercise 3a to include a member operator[] function
that has a double-precision grade count argument. The function should check the grade
count data member and, if fewer than four grades have been entered, store its argument in
the grade array, using the count as an index value. If four grades have already been entered,
the function should return an error message indicating that the new grade can’t be accepted.
Additionally, a new grade should force an increment to the count data member.

#include "stdafx.h" 
#include <iostream>
#include <iomanip>
using namespace std;
// class declaration section
class Student
{
private:
	int IDnum;
	int count;
	double arr[4];
public:
	Student(int = 0, int = 0, double = 0);    // constructor
	Student operator[](int);   // function prototype
	void showStudent();        // member function to display a Student
};
// class implementation section
Student::Student(int ii, int cc, double aa)
{
	IDnum = ii;
	count = cc;
	arr[count]= aa;

}
Student Student::operator[](int counts)
{
	Student temp;
	temp.count = count + counts;
	while (temp.count > 4){
		cout << "Error new grade can't be accepted" << endl;
		break;
	}
	while (temp.count <= 4){
	   arr[count]++;
	}
	return temp;
}
void Student::showStudent()
{
	for (count = 1; count < 4; count++) {
		IDnum = count * rand() %1000;
		arr[count] = rand() % 100 + 70;
	}
	double ans = ((arr[0] + arr[1] + arr[2] + arr[3]) / 4);
	cout <<"The student with ID number " << IDnum << " Average is " << ans << endl;
	return;
}
int main()
{
	Student a,b,c; // declare two objects
	cout << "The Student's info is "<< endl;
	a.showStudent();
	b.showStudent();
	c = a[5, 6, 7];
	c.showStudent();


	system("PAUSE");
	return 0;
}

c. Modify the class constructed for Exercise 3a to include a member operator() function
that has a grade index and grade value as arguments. The function should force a change to
the grade corresponding to the index value and update the count, if necessary. For example,
an argument list of 4, 98.5 should change the fourth test grade value to 98.5.

#include "stdafx.h" 
#include <iostream>
#include <iomanip>
using namespace std;
// class declaration section
class Student
{
private:
		int IDnum;
		int count;
		double arr[4];
public:
		Student(int = 0, int = 0, double = 0);    // constructor
		Student operator()(int , double);   // function prototype
		void showStudent();        // member function to display a Student
};
// class implementation section
Student::Student(int ii, int cc, double aa)
{
		IDnum = ii;
		count = cc;
		arr[count] = aa;
}


void Student::showStudent()
{
	double ans = 0;
		for (count = 0; count < 4; count++) {
			IDnum = rand() % 10000;
				arr[count] = rand() % 100;
				ans += arr[count];
		}
		cout << "The student with ID number " << IDnum << " Average is " << (ans/4) << endl;
		return;
}

Student Student::operator()( int counts, double grade)
{
	Student temp;
	for (temp.count = 0; temp.count < 4; temp.count++){

	if(temp.count == counts){
		temp.arr[counts] = grade;
	}
}
	return temp;
}
int main()
{
		Student a, b, c; // declare two objects
		cout << "The Student's info is " << endl;
		a.showStudent();
		b.showStudent();
		c = a(3,98.5);
		
		c.showStudent();
		system("PAUSE");
		return 0;
}

4. (Modify) a. Modify Program 10.9 to include a member operator[] function that multiplies
an object’s complex number (both the real and the imaginary parts) by a real number and
returns a complex number. For example, if the real number is 2 and the complex number is
3 + 4i, the result is 6 + 8i.

Done!!

b. Verify the operation of the operator[] function written for Exercise 4a by including it in
a working C++ program.

#include "stdafx.h" 
#include <iostream>
#include <cmath>
using namespace std;
// class declaration section
class Complex
{
	// friends list
	friend double addreal(Complex&, Complex&);
	friend double addimag(Complex&, Complex&);
private:
	double real;
	double imag;
public:
	Complex(double = 5.6, double = 4.5);  // constructor
	Complex operator[](double);
	void display();
};
// class implementation section
Complex::Complex(double rl, double im)
{
	real = rl;
	imag = im;
}
void Complex::display()
{
	char sign = '+';
	if (imag < 0) sign = '-';
	cout << real << sign << abs(imag) << 'i';
	return;
}
// friend implementations
double addreal(Complex &a, Complex &b)
{
	return(a.real + b.real);
}
double addimag(Complex &a, Complex &b)
{
	return(a.imag + b.imag);
}
Complex Complex::operator[](double multi)
{
	Complex temp;
	temp = temp.real  * multi;
	return temp;
}
int main()
{
	Complex a(3.2, 5.6), b(1.1, -8.4);
	double re, im;
	cout << "\nThe first complex number is ";
	a.display();
	cout << "\nThe second complex number is ";
	b.display();
	re = addreal(a, b);
	im = addimag(a, b);
	Complex c(re, im);  // create a new Complex object
	cout << "\n\nThe sum of these two complex numbers is ";
	c.display();
	cout << endl;
	c = a[2];
	c.display();
	system("PAUSE");
	return 0;
}