to Dave Lander,Marilyn de Queiroz

[mike hengst]

I wanted to show you two the code you helped me build. There is only one problem left. I have to increment the student number for use on the displayGrades() method. I thought what I had in the constructor and get,set methods would work, but it is just not working. Anyways here is all the code so you can(maybe) see what I have going on. Thanks for all the help!

import java.text.*;
/**
 *  This class is to be used in the GradePoint class
 *
 *@author     Michael Hengst
 *@created    October 25, 2002
 */
public class Student {
    private static  char[]  letterGrades   = {'F', 'D', 'C', 'B', 'A'};
    private static  int[]   points         = {0, 1, 2, 3, 4};
    private static  int     studentNumber  = 100;
                    char[]  studentGrades  = new char[5];
                    int[]   gradePoints    = new int[5];
                    int     stuNo;

    /**
     *  Constructor for the Student object
     *  sets the student number for the class
     */
    public Student() {
        getStudentNumber();
    }

    /**
     *  Sets the grade attribute of the Student object
     *
     *@param  index        The index of the new grade value
     *@param  letterGrade  The new grade value
     */
    public void setGrade(int index, char letterGrade) {
        for(int i = 0; i < studentGrades.length; ++i) {
            if(letterGrade == letterGrades[i]) {
                studentGrades[index] = letterGrades[i];
                gradePoints[index] = points[i];
                break;
            }
        }
    }

    /**
     *  Sets the studentNumber attribute of the Student object
     */
    public void setStudentNumber(int studentNumber) {
        stuNo = studentNumber + 1;
    }

    /**
     *  Gets the studentNumber attribute of the Student object
     *
     *@return    The studentNumber value
     */
    public int getStudentNumber() {
        return stuNo;
    }

    /**
     *  This method formats the data to be displayed
     *
     *@return    the return is the appended String sb
     */
    public String toString() {
        System.out.println(" ");
        DecimalFormat  df  = new DecimalFormat("0.00");
        StringBuffer   sb  = new StringBuffer("Student " + stuNo);
        sb.append("\n Grades ");
        sb.append("\n Course 1: " + studentGrades[0] +
                " points " + df.format(gradePoints[0]));
        sb.append("\n Course 2: " + studentGrades[1] +
                " points " + df.format(gradePoints[1]));
        sb.append("\n Course 3: " + studentGrades[2] +
                " points " + df.format(gradePoints[2]));
        sb.append("\n Course 4: " + studentGrades[3] +
                " points " + df.format(gradePoints[3]));
        sb.append("\n Course 5: " + studentGrades[4] +
                " points " + df.format(gradePoints[4]));
        sb.append("\n GPA = " + df.format(calcGPA()));
        return sb.toString();
    }

    /**
     *  This method calculates the GPA based on the array values
     *
     *@return    The unformatted GPA
     */
    public double calcGPA() {
        double  total  = 0;
        int     z      = 0;
        for(int i = 0; i < 5; ++i) {
            z = gradePoints[i];
            total = total + z;
        }
        return (total / 5);
    }

}
/**
 *  Description of the Class
 *
 *@author     Michael Hengst    
 *@created    October 25, 2002
 */
public class GradePoint {
    private final static  char[]     VALIDGRADES  = {'F', 'D', 'C', 'B', 'A'};
    private final static  int[]      POINTS       = {0, 1, 2, 3, 4};
    Student[]  students     = new Student[2];
    private         boolean    valid;

    /**
     *  Gets the studentData attribute of the GradePoint object
     *
     *@return                The studentData value
     *@exception  Exception  Description of Exception
     */
    public char getStudentData() throws Exception {
        char    grade   = ' ';
        double  points  = 0;
        int     index   = 0;
        valid = false;
        for(int i = 0; i < 2; ++i) {
            for(int x = 0; x < 5; ++x) {
                System.out.println("Please enter grade for student " +
                        (i + 1));
                grade = (char)System.in.read();
                System.in.read();
                System.in.read();
                System.out.println("You entered " + grade);
                for(int y = 0; y < 5; ++y) {
                    valid = false;
                    if(grade == VALIDGRADES[y]) {
                        valid = true;
                        index = x;
                        break;
                    }
                }
                if(valid) {
                    students[i].setGrade(index, grade);
                }
                else {
                    --x;
                    System.out.println("Invalid grade entered");
                }
            }
        }
        return grade;
    }

    /**
     *   This method place the grade entered into the array
     *  and is called from main in TestGradePoint
     *@exception  Exception  Description of Exception
     */
    public void assignGrades() throws Exception {
//            for(int x = 0;x < 2;++x)
//        {
        instantiateStudents();
        getStudentData();
//        }
            displayGrades();
    }

    /**
     *  Instantiating the student
     */
    public void instantiateStudents() {
        for(int i = 0; i < 2; ++i) {
            students[i] = new Student();
        }
    }

    /**
     *  Method to display the grades and GPA
     *
     *@return    Description of the Returned Value
     */
    public String displayGrades() {
        String  x  = new String();
        for(int i = 0; i < 2; ++i) {
            System.out.println(students[i].toString());
        }
        return x;
    }
}  

The GradePoint class is called from a class named TestGradePoint which is not included.

[Ron Newman]

The static variable studentNumber is never incremented or otherwise changed after you initialize it to 100.
Also, one of your methods has a parameter named studentNumber, which will hide the static variable of the same name. This is legal but is bad practice.

[Bill Liteplo]

Mike,
This code looks [BOLD]a lot[/BOLD] better than your last post. Way to go!
I notice that your included code doesn't ever set the studentNumber, even though your comments for the constructor mention it.
I think the constructor is a fine place for it.
However, I would avoid having an argument named studentNumber in the method setStudentNumber and also a static variable studentNumber (same name).
I'm guessing you want the student number to start at 100 (maybe 101?), and go up statically from there. Fine.
Then redo setStudentNumber to read

private void setStudentNumber() {
  stuNo = studentNumber;
  studentNumber++;
}

or reverse the two lines in the method to start at 101.
Then just invoke setStudentNumber() in your constructor, and never again. (Notice I made the method private.) If you want the student Number to be determined by something other than a static incrementing variable, then you may need to change this.
Bill

[mike hengst]

Eureka!!!It works. Thanks for the pointer
stuNo = studentNumber;
studentNumber++;
I got it to work with
stuNo = studentNumber++;
after I realized that I had to call setStudentNumber from the constructor. Once I realized my error it worked. Then I come back to javaranch to find out that was correct. This is beautiful. I spent alot of time on this and learned quite a bit. Although I am happy to be done with this I am still way behind on other things. So before I ramble too long. Thanks for all the help everybody. I am sure I will be back later on, maybe I can even answer questions one day.
[ October 26, 2002: Message edited by: mike hengst ]