Confused on why code won't work

rdpenning

I'm fairly new to the java language but I can't seem to get my code to work. It is supposed to read an input file with names and 10 quiz scores for each person, then do a bubble sort until we have the top 8 scores, then create an average of those scores and give it a letter grade. The final output for each person is supposed to look like this:

Name: blah - Grade: B

The input file looks like this

Bill Brasky
81
82
98
74
76
91
88
82
92
87
next name
and so on

Here's what my code looks like:

[code]
import java.io.*;

public class StudentGrades
{
public static void main(String args[]) throws Exception
{
String LETTER;
final int SIZE = 10; // Number of quizzes
double score[] = new double[SIZE]; // Array used to store 10 quiz scores.
String stuName; // Used to store name.
int x;
x = 0;
final int LIMIT = SIZE;
String stuScoreString; // used to store what is read before changing to integer.
int stuScore = 0;
int pairsToCompare;
double gradeAvg;
gradeAvg = 0;
boolean switchOccurred;
boolean done;
double temp;
double totalGrade;
totalGrade = 0;
int y;
y = 0;
System.out.println("Student Grade Report by Russ Penning");

// Start the input read.
FileReader fr = new FileReader("scores.dat");
BufferedReader br = new BufferedReader(fr);

// This is the work done in the fillArray() method
while((stuName = br.readLine()) != null) // Use to read only the first line of the array before change to integer.
{
x = 0;
done = false;
while(x < LIMIT)
{
// Place value in array.
stuScoreString = br.readLine();
// Convert String to integer.
stuScore = Integer.parseInt(stuScoreString);
score[x] = stuScore;
x++; // Get ready for next input item.

} // End of input loop.
stuScore = x - 2;
pairsToCompare = stuScore - 1;

// This is the work done in the sortArray() method
switchOccurred = true; // set flag to true

while(switchOccurred == true)
{
x = 0;
switchOccurred = false;
while(x < pairsToCompare)
{
if(score[x] > score[x + 1])
{
temp = score[x + 1];
score[x+1] = score[x];
score[x] = temp;
switchOccurred = true;
}
x++;
}
pairsToCompare--;
}
while(x < stuScore)
{
totalGrade = (score[x+2] + totalGrade);
x++;
}
gradeAvg = totalGrade / 8;

// Call calculateGrades method here
LETTER = calculateGrades(gradeAvg);
}
x = 0;
while(x < y)
{
LETTER = "";
System.out.println("Name: " + stuName + " - Grade: " + LETTER);
x++;
}

br.close();
System.exit(0);

} // End of main() method.

// Write calculateGrades method here.
public static String calculateGrades(double gradeAvg)
{

String LETTER;

if(gradeAvg >= 90)
LETTER = "A";
else if (gradeAvg >= 80)
LETTER = "B";
else if (gradeAvg >= 70)
LETTER = "C";
else if (gradeAvg >= 60)
LETTER = "D";
else
LETTER = "F";

return LETTER;
}

} // End of StudentGrades class.
[/code]

If anyone has any idea what is wrong with my code... Please let me know.

Thanks, Russ

Josh Code

Try this:

[code]
import java.io.*;

public class StudentGrades
{
public static void main(String args[]) throws Exception
{
String LETTER;
final int SIZE = 10; // Number of quizzes
double score[] = new double[SIZE]; // Array used to store 10 quiz scores.
String stuName; // Used to store name.
final int LIMIT = SIZE;
String stuScoreString; // used to store what is read before changing to integer.
int stuScore = 0;
double gradeAvg;
gradeAvg = 0;
System.out.println("Student Grade Report by Russ Penning");

// Start the input read.
FileReader fr = new FileReader("scores.dat");
BufferedReader br = new BufferedReader(fr);

// This is the work done in the fillArray() method
while((stuName = br.readLine()) != null) // Use to read only the first line of the array before change to integer.
{
for (int x=0;x < LIMIT;x++)
{
// Place value in array.
stuScoreString = br.readLine();
// Convert String to integer.
stuScore = Integer.parseInt(stuScoreString);
score[x] = stuScore;

} // End of input loop.
sortScores(score);
gradeAvg = calcAverage(score);

// Call calculateGrades method here
LETTER = calculateGrades(gradeAvg);

System.out.println("Name: " + stuName + " - Grade: " + LETTER);
}

br.close();

} // End of main() method.

public static double calcAverage(double [] scores)
{
double total = 0;

for (int x=0;x score[x + 1])
{
double temp = score[x + 1];
score[x+1] = score[x];
score[x] = temp;
switchOccurred = true;
}
}
}

}

// Write calculateGrades method here.
public static String calculateGrades(double gradeAvg)
{

String LETTER;

if(gradeAvg >= 90)
LETTER = "A";
else if (gradeAvg >= 80)
LETTER = "B";
else if (gradeAvg >= 70)
LETTER = "C";
else if (gradeAvg >= 60)
LETTER = "D";
else
LETTER = "F";

return LETTER;
}

} // End of StudentGrades class.
[/code]

Josh Code

I just noticed that you want the top 8 average instead of average of all so here is the corrected version:

[code]
import java.io.*;

public class StudentGrades
{
public static void main(String args[]) throws Exception
{
String LETTER;
final int SIZE = 10; // Number of quizzes
double score[] = new double[SIZE]; // Array used to store 10 quiz scores.
String stuName; // Used to store name.
final int LIMIT = SIZE;
String stuScoreString; // used to store what is read before changing to integer.
int stuScore = 0;
double gradeAvg;
gradeAvg = 0;
System.out.println("Student Grade Report by Russ Penning");

// Start the input read.
FileReader fr = new FileReader("scores.dat");
BufferedReader br = new BufferedReader(fr);

// This is the work done in the fillArray() method
while((stuName = br.readLine()) != null) // Use to read only the first line of the array before change to integer.
{
for (int x=0;x < LIMIT;x++)
{
// Place value in array.
stuScoreString = br.readLine();
// Convert String to integer.
stuScore = Integer.parseInt(stuScoreString);
score[x] = stuScore;

} // End of input loop.
gradeAvg = calcAverageOfTop8(score);

// Call calculateGrades method here
LETTER = calculateGrades(gradeAvg);

System.out.println("Name: " + stuName + " - Grade: " + LETTER);
}

br.close();

} // End of main() method.

public static double calcAverageOfTop8(double [] scores)
{
sortScores(scores);
double top8Total=0;

for (int x=scores.length-8;x score[x + 1])
{
double temp = score[x + 1];
score[x+1] = score[x];
score[x] = temp;
switchOccurred = true;
}
}
}

}

// Write calculateGrades method here.
public static String calculateGrades(double gradeAvg)
{

String LETTER;

if(gradeAvg >= 90)
LETTER = "A";
else if (gradeAvg >= 80)
LETTER = "B";
else if (gradeAvg >= 70)
LETTER = "C";
else if (gradeAvg >= 60)
LETTER = "D";
else
LETTER = "F";

return LETTER;
}

} // End of StudentGrades class.
[/code]