Modify class GradeBook (GradeBook.cpp, and GradeBook.h) (attached) as follows:

a) Include a second private data member instructorName in the GradeBook class. It represents the course instructors name. The data type of the instructorName is a string.

b) Create a new setInstructorName function in the GradeBook class. The function sets the instructor name. It accepts a string argument and does not return anything.

c) Create a new getInstructorName function in the GradeBook class. The function retrieves the instructor name. It does not accept any argument and returns one string data.

d) Modify the constructor to accept two parametersone for the course name and one for the instructors name.

d) Modify member function displayMessage such that it will display the welcome message and course name, then outputs "This course is presented by: " followed by the instructors name.

e) Adjust all the necessary statements in the GradeBook.cpp file to display the required space(s) and line space(s).

// GradeBook.cpp

// GradeBook member-function definitions. This file contains

// implementations of the member functions prototyped in GradeBook.h.

#include

#include "GradeBook.h" // include definition of class GradeBook

using namespace std;

// constructor initializes courseName with string supplied as argument

GradeBook::GradeBook( string name )

: courseName( name ) // member initializer to initialize courseName

{

// empty body

} // end GradeBook constructor

// function to set the course name

void GradeBook::setCourseName( string name )

{

courseName = name; // store the course name in the object

} // end function setCourseName

// function to get the course name

string GradeBook::getCourseName() const

{

return courseName; // return object's courseName

} // end function getCourseName

// display a welcome message to the GradeBook user

void GradeBook::displayMessage() const

{

// call getCourseName to get the courseName

cout << "Welcome to the grade book for " << getCourseName()

<< "!" << endl;

} // end function displayMessage

// GradeBook.h

// GradeBook class definition. This file presents GradeBook's public

// interface without revealing the implementations of GradeBook's member

// functions, which are defined in GradeBook.cpp.

#include // class GradeBook uses C++ standard string class

// GradeBook class definition

class GradeBook

{

public:

explicit GradeBook( std::string ); // constructor initialize courseName

void setCourseName( std::string ); // sets the course name

std::string getCourseName() const; // gets the course name

void displayMessage() const; // displays a welcome message

private:

std::string courseName; // course name for this GradeBook

}; // end class GradeBook