Source of GradeBook.java


  1: // Fig. 4.6: GradeBook.java
  2: // GradeBook class that solves class-average problem using 
  3: // counter-controlled repetition.
  4: import java.util.Scanner; // program uses class Scanner
  5: 
  6: public class GradeBook 
  7: {
  8:    private String courseName; // name of course this GradeBook represents
  9: 
 10:    // constructor initializes courseName
 11:    public GradeBook( String name )
 12:    {
 13:       courseName = name; // initializes courseName
 14:    } // end constructor
 15: 
 16:    // method to set the course name
 17:    public void setCourseName( String name )
 18:    {
 19:       courseName = name; // store the course name
 20:    } // end method setCourseName
 21: 
 22:    // method to retrieve the course name
 23:    public String getCourseName()
 24:    {
 25:       return courseName;
 26:    } // end method getCourseName
 27: 
 28:    // display a welcome message to the GradeBook user
 29:    public void displayMessage()
 30:    {
 31:       // getCourseName gets the name of the course
 32:       System.out.printf( "Welcome to the grade book for\n%s!\n\n", 
 33:          getCourseName() );
 34:    } // end method displayMessage
 35: 
 36:    // determine class average based on 10 grades entered by user
 37:    public void determineClassAverage() 
 38:    {
 39:       // create Scanner to obtain input from command window
 40:       Scanner input = new Scanner( System.in );
 41: 
 42:       int total; // sum of grades entered by user
 43:       int gradeCounter; // number of the grade to be entered next
 44:       int grade; // grade value entered by user
 45:       int average; // average of grades
 46: 
 47:       // initialization phase
 48:       total = 0; // initialize total
 49:       gradeCounter = 1; // initialize loop counter
 50:    
 51:       // processing phase
 52:       while ( gradeCounter <= 10 ) // loop 10 times
 53:       {
 54:          System.out.print( "Enter grade: " ); // prompt 
 55:          grade = input.nextInt(); // read grade from user
 56:          total = total + grade; // add grade to total
 57:          gradeCounter = gradeCounter + 1; // increment counter by 1
 58:       } // end while
 59:    
 60:       // termination phase
 61:       average = total / 10; // integer division yields integer result
 62: 
 63:       // display total and average of grades
 64:       System.out.printf( "\nTotal of all 10 grades is %d\n", total );
 65:       System.out.printf( "Class average is %d\n", average );
 66:    } // end method determineClassAverage
 67: 
 68: } // end class GradeBook
 69: 
 70: /**************************************************************************
 71:  * (C) Copyright 1992-2005 by Deitel & Associates, Inc. and               *
 72:  * Pearson Education, Inc. All Rights Reserved.                           *
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