1   // Fig. 4.6: GradeBook.h
 2   // Definition of class GradeBook that determines a class average.
 3   // Member functions are defined in GradeBook.cpp
 4   #include <string> // program uses C++ standard string class
 5
 6   // GradeBook class definition
 7   class GradeBook
 8   {
 9   public:
10      explicit GradeBook( std::string ); // initializes course name
11      void setCourseName( std::string ); // set the course name
12      std::string getCourseName() const; // retrieve the course name
13      void displayMessage() const; // display a welcome message
14      void determineClassAverage() const; // averages user-entered grades
15   private:
16      std::string courseName; // course name for this GradeBook
17   }; // end class GradeBook

 1   // Fig. 4.7: GradeBook.cpp
 2   // Member-function definitions for class GradeBook that solves the
 3   // class average program with counter-controlled repetition.
 4   #include <iostream>
 5   #include "GradeBook.h" // include definition of class GradeBook
 6   using namespace std;
 7
 8   // constructor initializes courseName with string supplied as argument
 9   GradeBook::GradeBook( string name )
10   {
11      setCourseName( name ); // validate and store courseName
12   } // end GradeBook constructor
13
14   // function to set the course name;
15   // ensures that the course name has at most 25 characters
16   void GradeBook::setCourseName( string name )
17   {
18      if ( name.size() <= 25 ) // if name has 25 or fewer characters
19         courseName = name; // store the course name in the object
20      else // if name is longer than 25 characters
21      { // set courseName to first 25 characters of parameter name
22         courseName = name.substr( 0, 25 ); // select first 25 characters
23         cerr << "Name "" << name << "" exceeds maximum length (25). "
24            << "Limiting courseName to first 25 characters. " << endl;
25      } // end if...else
26   } // end function setCourseName
27
28   // function to retrieve the course name
29   string GradeBook::getCourseName() const
30   {
31      return courseName;
32   } // end function getCourseName
33
34   // display a welcome message to the GradeBook user
35   void GradeBook::displayMessage() const
36   {
37      cout << "Welcome to the grade book for " << getCourseName() << "! "
38         << endl;
39   } // end function displayMessage
40
41   // determine class average based on 10 grades entered by user
42   void GradeBook::determineClassAverage() const
43   {
44      // initialization phase
45      int total = 0; // sum of grades entered by user
46      unsigned int gradeCounter = 1; // number of grade to be entered next
47
48      // processing phase
49      while ( gradeCounter <= 10 ) // loop 10 times
50      {
51         cout << "Enter grade: "; // prompt for input
52         int grade = 0; // grade value entered by user
53         cin >> grade; // input next grade
54         total = total + grade; // add grade to total
55         gradeCounter = gradeCounter + 1; // increment counter by 1
56      } // end while
57
58      // termination phase
59      int average = total / 10; // ok to mix declaration and calculation
60
61      // display total and average of grades
62      cout << " Total of all 10 grades is " << total << endl;
63      cout << "Class average is " << average << endl;
64   } // end function determineClassAverage

 1   // Fig. 4.8: fig04_08.cpp
 2   // Create GradeBook object and invoke its determineClassAverage function.
 3   #include "GradeBook.h" // include definition of class GradeBook
 4
 5   int main()
 6   {
 7      // create GradeBook object myGradeBook and
 8      // pass course name to constructor
 9      GradeBook myGradeBook( "CS101 C++ Programming" );
10
11      myGradeBook.displayMessage(); // display welcome message
12      myGradeBook.determineClassAverage(); // find average of 10 grades
13   } // end main