// Fig. 4.13: GradeBook.cpp // Member-function definitions for class GradeBook that solves the // class average program with sentinel-controlled repetition. #include using std::cout; using std::cin; using std::endl; using std::fixed; // ensures that decimal point is displayed #include // parameterized stream manipulators using std::setprecision; // sets numeric output precision // include definition of class GradeBook from GradeBook.h #include "GradeBook.h" // constructor initializes courseName with string supplied as argument GradeBook::GradeBook( string name ) { setCourseName( name ); // validate and store courseName } // end GradeBook constructor // function to set the course name; // ensures that the course name has at most 25 characters void GradeBook::setCourseName( string name ) { if ( name.length() <= 25 ) // if name has 25 or fewer characters courseName = name; // store the course name in the object else // if name is longer than 25 characters { // set courseName to first 25 characters of parameter name courseName = name.substr( 0, 25 ); // select first 25 characters cout << "Name \"" << name << "\" exceeds maximum length (25).\n" << "Limiting courseName to first 25 characters.\n" << endl; } // end if...else } // end function setCourseName // function to retrieve the course name string GradeBook::getCourseName() { return courseName; } // end function getCourseName // display a welcome message to the GradeBook user void GradeBook::displayMessage() { cout << "Welcome to the grade book for\n" << getCourseName() << "!\n" << endl; } // end function displayMessage // determine class average based on 10 grades entered by user void GradeBook::determineClassAverage() { int total; // sum of grades entered by user int gradeCounter; // number of grades entered int grade; // grade value double average; // number with decimal point for average // initialization phase total = 0; // initialize total gradeCounter = 0; // initialize loop counter // processing phase // prompt for input and read grade from user cout << "Enter grade or -1 to quit: "; cin >> grade; // input grade or sentinel value // loop until sentinel value read from user while ( grade != -1 ) // while grade is not -1 { total = total + grade; // add grade to total gradeCounter = gradeCounter + 1; // increment counter // prompt for input and read next grade from user cout << "Enter grade or -1 to quit: "; cin >> grade; // input grade or sentinel value } // end while // termination phase if ( gradeCounter != 0 ) // if user entered at least one grade... { // calculate average of all grades entered average = static_cast< double >( total ) / gradeCounter; // display total and average (with two digits of precision) cout << "\nTotal of all " << gradeCounter << " grades entered is " << total << endl; cout << "Class average is " << setprecision( 2 ) << fixed << average << endl; } // end if else // no grades were entered, so output appropriate message cout << "No grades were entered" << endl; } // end function determineClassAverage /************************************************************************** * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and * * Pearson Education, Inc. All Rights Reserved. * * * * DISCLAIMER: The authors and publisher of this book have used their * * best efforts in preparing the book. These efforts include the * * development, research, and testing of the theories and programs * * to determine their effectiveness. The authors and publisher make * * no warranty of any kind, expressed or implied, with regard to these * * programs or to the documentation contained in these books. The authors * * and publisher shall not be liable in any event for incidental or * * consequential damages in connection with, or arising out of, the * * furnishing, performance, or use of these programs. * **************************************************************************/