GradeBook OOP example from the Book C How to Program

GradeBook.cpp

// GradeBook Implementation

#include <iostream>
using std::cout;
using std::endl;

#include "GradeBook.h" // include interface

// constructor implementation
GradeBook::GradeBook(string name){
    setCourseName( name ); // validate and store courseName
}

// setCourseName implementation
// ensures that the course name has at most 25 characters
void GradeBook::setCourseName( string name ){
    if ( name.length() <= 25 )
        courseName = name;

    if ( name.length() > 25 ){
        courseName = name.substr(0, 25); // start at 0 and end at 25

        cout << "Name \"" << name << "\" exceeds maximum length (25). \n"
                << "Limiting courtName to first 25 characters.\n" << endl;
    }
}

// getCourseName implementation
string GradeBook::getCourseName(){
    return courseName; // return object's courseName
}

// display a welcome message to the GradeBook user
void GradeBook::displayMessage(){
    cout << "Welcome to the grade book for\n" << getCourseName()
            << "!" << endl;
}

GradeBook.h

// Gradebook interface

#include <string>
using std::string;

class GradeBook{
    public:
        GradeBook( string ); // GradeBook constructor
        void setCourseName( string ); // setter function
        string getCourseName(); // getter function
        void displayMessage();  // display welcome message
   private:
        string courseName; // course name for GradeBook
};

main.cpp

// GradeBook main program
#include <iostream>
using std::cout;
using std::endl;

#include "GradeBook.h" // include GradeBook header file

int main(){
    // Create two GradeBook objects
    GradeBook gradeBook1( "CS101 Introduction to programming in C++" );
    GradeBook gradeBook2( "CS102 C++ Data Structures" );

    cout << "gradeBook1's initial course name is: "
            << gradeBook1.getCourseName()
            << "\ngradeBook2's initial course name is:"
            << gradeBook2.getCourseName() << endl;

    gradeBook1.setCourseName( "CS101 C++ Programming" );

    // display each GradeBook's courseName
    cout << "\ngradeBook1's course name is: "
            << gradeBook1.getCourseName()
            << "\ngradeBook2's course name is: "
            << gradeBook2.getCourseName() << endl;

    return 0;
}