We Keep Coding

how to position this java while loop?

So the while loop is not working, even though it compiles.  How do I position it correctly??
I tried a few things but they kinda worked. if someone on here can help me out that would be great
import java.util.Scanner;
//This is a Driver program to test the external Class named Student
public class StudentDriver //BEGIN Class Definition
{
//**************** Main Method*************************
public static void main (String[] args)
{Scanner scan = new Scanner(System.in);
//Data Definitions:
//Instance Data
String courseName;
int courseCredits;
String name;
String id;
String street;
String city;
String state;
String zip;
String major;
//Executable Statements:
//Initialize first Student
name = "Fred Fergel";
id = "0123";
street = "123 Main Street";
city = "Smalltown";
state = "NY";
zip = "12345";
major = "Computer Science";
//instantiate the Student object
Student student1 = new Student(name, id, street, city, state, zip, major);
//Test toString
System.out.println("Student 1\n\n" + student1.toString());
//Print a blank line
System.out.println();
//Add a course
student1.addCourse("CSC111", 4);//NOTE:  DO NOT PUT A SPACE BETWEEN CSC AND 111
//Print schedule
System.out.println("Student 1's Schedule:\n\n");
student1.displaySchedule();//call method
final String FLAG = "Y";
String prompt = "Y";
while (prompt.equals("y"))
{
System.out.println("Please enter the name of the course: ");
courseName = scan.next();
System.out.println("How many credits is the course? ");
courseCredits = scan.nextInt();
student1.addCourse(courseName, courseCredits);
System.out.println("Do you wish to enter another course? y/n");
prompt = scan.next();
}
//end while
}//end main
}//end StudentDriver
Here is the student class:
import java.util.Scanner;
public class Student
{Scanner scan = new Scanner(System.in);
//Instance Data
String studentName;
String studentID;
String streetAddress;
String city;
String state;
String zipCode;
String major;
int totalCredits;
final int SIZE = 6;
final int MAX_CREDITS = 18;
String [ ] schedule = new String [SIZE];
int courseNumber = 0; //start out with no courses
//Create Constructor:
//Initializes the student data at instantiation time.
//-------------------------------------------------------
// Sets up the student's information.
//-------------------------------------------------------
public Student (String name, String id, String address, String cityName, String stateName, String zip, String area )
{
studentName = name;
studentID = id;
streetAddress = address;
city = cityName;
state = stateName;
zipCode = zip;
major = area;
}//end Student Constructor
//Method to Return student information as string:
//-------------------------------------------------------
// Returns the student information as a formatted string.
//-------------------------------------------------------
public String toString()
{
String studentInfo;
studentInfo = "Name:\t\t\t" + studentName + "\n" + "ID:\t\t\t" + studentID + "\n" + "Address:\t\t" + streetAddress
+ "\n" + "City:\t\t\t" + city + "\n" + "State:\t\t\t" + state + "\n" + "Zip Code:\t\t" + zipCode
+ "\n" + "Major:\t\t\t" + major + "\n";
return studentInfo;
}// end toString
//Method to determine if maximum allowed credits have been exceeded
//-------------------------------------------------------
// Returns true if total credits does not exceed 18.
//-------------------------------------------------------
private boolean checkCredits(int numCredits)
{
if (numCredits + totalCredits <= MAX_CREDITS) //make sure max credits not exceeded
{
return true; //return a true if still less than 18 credits
}
else
{
return false; //return a false if 18 credit limit is exceeded
}//end numCredits
}//checkCredits
//Method to add a course to the student’s schedule
//-------------------------------------------------------
// Adds a course to the array if total credits does not exceed 18.
//-------------------------------------------------------
public void addCourse(String course, int numCredits)
{
if (courseNumber < SIZE ) //make sure array is not full.
{
if (checkCredits(numCredits) == true) //if we’re under 18 credits
{
//add course
schedule [courseNumber] = course + ":\t\t" + numCredits + "\tCredits\n";
//increment number of credits
totalCredits = totalCredits + numCredits;
//increment number of courses
courseNumber = courseNumber + 1;
}
else //oops – can’t do more than 18 credits
{
System.out.println("You have exceeded the maximum allowed credits.");
}//end checkCredits
}
else //oops – can’t do more than 10 courses
{
System.out.println("You have exceeded 10 courses.");
}//end courseNumber
}//addCourse
//Method to display the schedule
//-------------------------------------------------------
// Will only print out the courses added to the array.
//-------------------------------------------------------
public void displaySchedule( )
{
for (int index = 0; index < courseNumber; index++)
{
System.out.println("Course #" + (index + 1) + " " + schedule[index] + "\n");
}//end for
}//end display schedule
}

String prompt = "Y";
while (prompt.equals("y"))
Y and y are not the same thing. You need to use .equalsIgnoreCase() instead of .equals() if you want it to ignore case.

My program is printing only the last input from the ArrayList

I have another small class containing the main method that display the
invoice, but the toString method here is only displaying the last item
entered, not the three itemnames,quantities, prices and totalPrice.
I have doubts about addItemLine and toString.
Can someone see what I am missing here?
I was enable to past the lineItem class code.
import java.util.ArrayList;
import java.util.Scanner;
public class Transaction {
private ArrayList<lineItem> lineItems;
private int customerID;
private String customerName;
public Transaction (int customerID, String customerName){
this.customerID= customerID;
this.customerName= customerName;
this.lineItems= new ArrayList<>();
}
public int getcustomerID(){
return customerID;
}
public void setcustomerID(int customerID){
this.customerID = customerID;
}
public String getcustomerName(){
return customerName;
}
public void setcustomerName(String customerName){
this.customerName = customerName;
}
public ArrayList addItemLine(lineItem line){
Scanner mykey=new Scanner(System.in);
for (int i=0; i<2;i++){
String k= line.getItemName();
int m= line.getQuantity();
double d= line.getPrice();
System.out.println("enter item name:");
k = mykey.next();
line.setItemName(k);
System.out.println("enter quantity:");
m= mykey.nextInt();
line.setQuantity(m);
System.out.println("enter unit price:");
d= mykey.nextDouble();
line.setPrice(d);
line.getItemName(); line.getQuantity(); line.getPrice();
lineItems.add(new lineItem(k,m,d));
}
return this.lineItems;
}
public void updateItem(String item, int quant, double pri){
lineItem l= new lineItem(item, quant, pri);
int m=0;
m= l.getQuantity();
m=m+quant;
double tot=0;
}
public double getTotalPrice(){
double totalPrice = 0;
for (int i =0;i<2; i++){
lineItem item = lineItems.get(i);
totalPrice = totalPrice + item.getTotalPrice();
}
return totalPrice;
}
public String getLineItem( String s, int d, double k){
lineItem o= new lineItem(s,d,k);
for (int i =0;i<2; i++){
if (!s.equals(o.getItemName()))
System.out.println("item not found");
else
s= (o.getItemName() + o.getQuantity() + o.getPrice());
}
return s;
}
public String toString(lineItem lin) {
String a="", b="";
a=("Customer ID:" + this.getcustomerID() + "\n" + "Customer Name: " +
this.getcustomerName());
for (int i=0; i<2;i++){
b= ("\n\n" + lin.getItemName() + "\t" + "Qty" + lin.getQuantity() + "
"
+ "#" + lin.getPrice() + " "+ "\t" + "$" + lin.getTotalPrice());
}
return a + b;
}
TransactionTesting:
import java.util.Scanner;
public class TransactionTesting {
public static void main(String args[]) {
String m=""; int g=0; double r=0; int id=0; String name="";
Scanner mykey= new Scanner(System.in);
System.out.println("enter customer name:");
name= mykey.nextLine();
System.out.println("enter customer ID:");
id=mykey.nextInt();
Transaction mytrans= new Transaction(id, name);
lineItem line= new lineItem(m,g,r);
mytrans.addItemLine(line);
System.out.println(mytrans.toString(line));
}
}

Change your toString() method like this:
public String toString() {
String a="", b="";
a=("Customer ID:" + this.getcustomerID() + "\n" + "Customer Name: " +
this.getcustomerName());
for (lineItem item : this.lineItems)
b += ("\n\n" + item.getItemName() + "\t" + "Qty" + item.getQuantity() + " "
+ "#" + item.getPrice() + " "+ "\t" + "$" + item.getPrice());
return a + b;
}
and from your test class call this method as the following:
System.out.println(mytrans.toString());
You don't need any argument in order to print your entire list.
Try to refactor your code a bit. It works, but it can be written better and better ;)

1) The call
System.out.println(mytrans.toString(line));
is printing out the single lineitem that is passed to it. What you probably intended was for Transaction.toString() to iterate over its list Transaction.lineItems and print each item in turn.
In fact Transaction.toString() doesn't need to take in a lineItem argument, the method should merely print out the internals of the class instance.
2) There is a similar confusion in Transacton.addItemLine(). It accepts a lineItem, prompts the user for new values, updates lineItem.. then constructs a new lineItem to store in Transaction.lineItems. It isn't actually causing a bug that I can see but you should get rid of the lineItem argument entirely; addItemLine doesn't need it.
3) Incidentally:
for (int i=0; i<2;i++){ }
loops twice, not three times. I trust you would have caught that in testing.
4) There is also a line of code near the end of addItemLine that doesn't actually do anything! Maybe you can spot that one on your own.
There are some other issues but those are the ones that leapt out at me.

Just a quick non-tested solution that may work. Something is copied from your code, something is changed because your code was wrong.
// If you create this inside the method than you'll lose everything everytime you call addItemLine
private ArrayList<lineItem> lineItems;
public void addItemLine(lineItem line){
Scanner mykey=new Scanner(System.in);
for (int i=0; i<2;i++){
String k= line.getItemName();
int m= line.getQuantity();
double d= line.getPrice();
System.out.println("enter item name:");
k = mykey.next();
line.setItemName(k);
System.out.println("enter quantity:");
m= mykey.nextInt();
line.setQuantity(m);
System.out.println("enter unit price:");
d= mykey.nextDouble();
line.setPrice(d);
line.getItemName(); line.getQuantity(); line.getPrice();
lineItems.add(new lineItem(k,m,d));
// This doesn't have to return anything, it just adds to the list
}
// No parameteres, this should build the string for the current object
public String toString() {
// String concatenation is not the best idea, StringBuilder is better
StringBuilder sb = new StringBuilder();
// If you want to print all of them then you need to iterate over the list
for (lineItem item : lineItems){
sb.append("Customer ID:" + this.getcustomerID() + "\n" + "Customer Name: " + this.getcustomerName());
for (int i=0; i<2;i++){
// Copied from your code
sb.append("\n\n" + lin.getItemName() + "\t" + "Qty" + lin.getQuantity() + " "+ "#" + lin.getPrice() + " "+ "\t" + "$" + lin.getTotalPrice());
}
sb.append("\n);
}
return sb.toString();
}

It seems that you don't understand how to create a Java object, or how to keep your application model separate from your application view.
Here's a test run of your code, after I made some changes.
Enter customer name: Gilbert
Enter customer ID: 123
Enter item name: Spinach
Enter quantity: 5
Enter unit price: .89
Customer ID: 123
Customer Name: Gilbert
Spinach Qty 5 #0.89 $4.45
Enter item name: Corn
Enter quantity: 12
Enter unit price: .29
Customer ID: 123
Customer Name: Gilbert
Corn Qty 12 #0.29 $3.4799999999999995
Enter item name:
First, let's look at your Java objects. The first Java object which you didn't include, is LineItem. Note that Java class names start with a capital letter.
package com.ggl.transaction;
public class LineItem {
private String itemName;
private int quantity;
private double price;
public LineItem(String itemName, int quantity, double price) {
this.itemName = itemName;
this.quantity = quantity;
this.price = price;
}
public String getItemName() {
return itemName;
}
public void setItemName(String itemName) {
this.itemName = itemName;
}
public int getQuantity() {
return quantity;
}
public void setQuantity(int quantity) {
this.quantity = quantity;
}
public double getPrice() {
return price;
}
public void setPrice(double price) {
this.price = price;
}
public double getTotalPrice() {
return price * quantity;
}
}
A Java object consists of class fields, and getters and setters for the fields.
Next, here's your Transaction class.
package com.ggl.transaction;
import java.util.ArrayList;
import java.util.List;
public class Transaction {
private List<LineItem> lineItems;
private int customerID;
private String customerName;
public Transaction(int customerID, String customerName) {
this.customerID = customerID;
this.customerName = customerName;
this.lineItems = new ArrayList<>();
}
public int getcustomerID() {
return customerID;
}
public void setcustomerID(int customerID) {
this.customerID = customerID;
}
public String getcustomerName() {
return customerName;
}
public void setcustomerName(String customerName) {
this.customerName = customerName;
}
public void addItemLine(LineItem line) {
this.lineItems.add(line);
}
public void updateItem(String item, int quant, double pri) {
LineItem l = new LineItem(item, quant, pri);
int m = 0;
m = l.getQuantity();
m = m + quant;
l.setQuantity(m);
}
public double getTotalPrice() {
double totalPrice = 0;
for (int i = 0; i < 2; i++) {
LineItem item = lineItems.get(i);
totalPrice = totalPrice + item.getTotalPrice();
}
return totalPrice;
}
public String getLineItem(String s, int d, double k) {
LineItem o = new LineItem(s, d, k);
for (int i = 0; i < 2; i++) {
if (!s.equals(o.getItemName()))
System.out.println("item not found");
else
s = (o.getItemName() + o.getQuantity() + o.getPrice());
}
return s;
}
public String toItemString(LineItem lin) {
String b = "";
String a = ("Customer ID: " + this.getcustomerID() + "\n"
+ "Customer Name: " + this.getcustomerName());
for (int i = 0; i < 2; i++) {
b = ("\n\n" + lin.getItemName() + "\t" + "Qty " + lin.getQuantity()
+ " " + "#" + lin.getPrice() + " " + "\t" + "$"
+ lin.getTotalPrice() + "\n");
}
return a + b;
}
}
I simplified your addItemLine class. Code that receives input using the Scanner class belongs in your TransactionTesting class.
I renamed your toString method to toItemString. toString is a method of the Object class. Since your method has a parameter, I renamed it to lessen any confusion.
Finally, here's your TransactionTesting class. I fixed it up so it would work. You can specify any number of line items. To stop processing, just enter a blank item name.
package com.ggl.transaction;
import java.util.Scanner;
public class TransactionTesting {
public static void main(String args[]) {
Scanner mykey = new Scanner(System.in);
System.out.print("Enter customer name: ");
String name = mykey.nextLine().trim();
System.out.print("Enter customer ID: ");
int id = Integer.valueOf(mykey.nextLine().trim());
Transaction mytrans = new Transaction(id, name);
boolean processing = true;
while (processing) {
System.out.print("Enter item name: ");
String k = mykey.nextLine().trim();
if (k.equals("")) {
processing = false;
} else {
System.out.print("Enter quantity: ");
int m = Integer.valueOf(mykey.nextLine().trim());
System.out.print("Enter unit price: ");
double d = Double.valueOf(mykey.nextLine().trim());
LineItem lineItem = new LineItem(k, m, d);
mytrans.addItemLine(lineItem);
System.out.println("\n" + mytrans.toItemString(lineItem));
}
}
mykey.close();
}
}
Remember, keep your application model (LineItem & Transaction) separate from your application view (TransactionTesting).

Simply put, in your method "addItemLine" you take data from 1 lineItem, overwrite it with some keyboard input, and the put in the list 2 other lineItem instances.
Then in the test code you print the original lineItem, which is not even in the list.
The method itself iterates on nothing, just creates twice the same string "b".
I suggest you to look at some tutorials on arrays and for loops.

Java highest score

Okay so i'm trying to make a program to display the top 2 highest scorers of 5 students only.
So sample output.
Enter your name : Spear
Enter score : 56
Enter your name : Sky
Enter score : 61
Enter your name : Spy
Enter score : 45
Enter your name : Raks
Enter score : 31
Enter your name : Felicio
Enter score : 39
Congratulations Sky!
Congratulations Spear!
I only know how to take the largest score and not the second here is what i got so far.
import java.util.Scanner;
public class Highest{
public static void main(String[]args) {
Scanner x = new Scanner(System.in);
String name = "";
int score;
int k;
int highest = 0;
num = x.nextLine();
largest = num;
for (int i = 0; i <= 5; i++) {
System.out.print("Enter name: ");
k = x.nextInt();
System.out.print("Enter score: ");
num = x.nextInt();
if (num > highest) {
highest = num;
}
}
System.out.println(largest);
}
} // how do i display the name of the highest score and the second placer?

You may want to look at sorting methods to solve such problems in the future e.g. sorting Arrays and sorting collections
For your particular case where you want to select the two max elements you can simply use two variables
int highestScore = 0;
String highestName = "";
int secondScore = 0;
String secondName = "";
and then
if (num > highestScore) {
secondScore = highestScore;
secondName = highestName;
highestScore = num;
highestName = name;
} else if (num > secondScore) {
secondScore = num;
secondName = name;
}
The code may be cleaner if you define a Student class to hold score and name.
Printing is straightforward
System.out.printnl("Congratulations " + highestName + "!");
System.out.printnl("Congratulations " + secondName + "!");

To expand on what Manos said:
You probably want to create a class for your students:
class Student {
private String name;
private int score;
Student(String name, int score) {
this.name = name;
this.score = score;
}
public int getScore() {
return this.score;
}
public String getName() {
return this.name;
}
}
You can then add each student to a collection and use a Comparator to sort your students:
Collections.sort(students, new Comparator<Student>() {
public int compare(Student o1, Student o2) {
return Integer.compare(o1.getScore(), o2.getScore());
}
});
The resulting collection will hold a list where the highest scoreing students will be at the far end of the collection, or you can then reverse the collection so they are at the begining instead:
Collections.reverse(students);
Full example:
public static void main(String[] args) {
class Student {
private String name;
private int score;
Student(String name, int score) {
this.name = name;
this.score = score;
}
public int getScore() {
return this.score;
}
public String getName() {
return this.name;
}
}
ArrayList<Student> students = new ArrayList<>();
for (int i = 0; i < 10; i++) {
java.util.Random rand = new java.util.Random();
Student s = new Student("Student " + i, rand.nextInt());
students.add(s);
}
Collections.sort(students, new Comparator<Student>() {
public int compare(Student o1, Student o2) {
return Integer.compare(o1.getScore(), o2.getScore());
}
});
Collections.reverse(students);
System.out.println("Highest scoring student: " + students.get(0).getName() + " with a score of " + students.get(0).getScore());
System.out.println("Highest scoring student: " + students.get(1).getName() + " with a score of " + students.get(1).getScore());
// List all students (Java 8 only...)
students.forEach( x -> System.out.println("Name: " + x.getName() + " with score: " + x.getScore()) );
}

Copy Constructor Test not Working (Java)

I'm working on CS homework and have run into a problem. The end of the homework asks about using a copy constructor. The goal is to "make one Payroll object, instantiate it, make a second one, then print them both. Then, change values in the second Payroll object, and show that the changed values only appear in one and not both (that is, print out the original and the copy with slightly changed values)." I tried changing the values in the second Payroll object, but it also changes it in the first. I've listed my code below:
import java.util.Random;
public class Payroll {
private int[] employeeId;
private int[] hours;
private double[] payRate;
public Payroll(){
this.employeeId = new int[0];
this.hours = new int[0];
this.payRate = new double[0];
}
public Payroll(Payroll obj){
this.employeeId = obj.employeeId;
this.hours = obj.hours;
this.payRate = obj.payRate;
}
public Payroll(int i){
this.employeeId = new int[i];
this.hours = new int[i];
this.payRate = new double[i];
}
public int getEmployeeIdAt(int index){
return employeeId[index];
}
public int getHoursAt(int index){
return hours[index];
}
public double getPayRateAt(int index){
return payRate[index];
}
public double getGrossPay(int index){
double grossPay = hours[index] * payRate[index];
grossPay = Math.round(grossPay * 100);
return grossPay/100;
}
public void setEmployeeIdAt(int index, int id){
this.employeeId[index] = id;
}
public void setHoursAt(int index, int hrs){
this.hours[index] = hrs;
}
public void setPayRateAt(int index, double pr){
this.payRate[index] = pr;
}
public void setHoursAt(int i){
Random rand = new Random();
int randHours = rand.nextInt((50 - 15) + 1) + 15;
this.hours[i] = randHours;
}
}
import java.util.Scanner;
public class PayrollDriver {
public static void main(String[] args) {
Payroll pr = new Payroll(5);
Scanner scan = new Scanner(System.in);
int empID = 1001;
for(int i = 0; i < 5; i++){
pr.setEmployeeIdAt(i, empID);
empID++;
}
for(int i = 0; i < 5; i++){
System.out.println("Enter the hourly pay rate for employee number " + pr.getEmployeeIdAt(i) + ": ");
double payRate = scan.nextDouble();
if(payRate < 7.50){
do{
System.out.println("ERROR: Enter 7.50 or greater for pay rate: ");
payRate = scan.nextDouble();
} while(payRate < 7.50);
}
pr.setPayRateAt(i, payRate);
pr.setHoursAt(i);
}
System.out.println("PAYROLL DATA");
System.out.println("======================");
for(int i = 0; i < 5; i++){
System.out.println("Employee ID: " + pr.getEmployeeIdAt(i) + " Hours: " + pr.getHoursAt(i) + " Rate: " + pr.getPayRateAt(i) +
" Gross Pay: $" + pr.getGrossPay(i));
}
System.out.println("Would you like to run the Copy Constructor Test? Enter 'y' (lowercase) if yes, enter any other letter if no: ");
char copyTestVerify = scan.next().charAt(0);
if(copyTestVerify == 'y'){
CopyConstructorTest ct = new CopyConstructorTest();
ct.CopyTest();
}
scan.close();
}
}
The following is my CopyConstructorTest class, the one that tests whether or not the copy constructor will change the original object's values:
public class CopyConstructorTest {
public void CopyTest(){
Payroll pay = new Payroll(5);
pay.setEmployeeIdAt(0, 1001);
Payroll payCopy = new Payroll(pay);
System.out.println("Original: " + pay.getEmployeeIdAt(0));
System.out.println("Copy: " + payCopy.getEmployeeIdAt(0));
payCopy.setEmployeeIdAt(0, 5000);
System.out.println("Original after changes: " + pay.getEmployeeIdAt(0));
System.out.println("Copy after changes: " + payCopy.getEmployeeIdAt(0));
}
}
I'm not positive on what I'm doing wrong. Any help or guidance is much appreciated.

You are just copying the references to the arrays, not the actual data. Therefore whenever you change the data in one of your objects, the changes are seen in both, since they point to the same array.
The easiest way to copy the data is probably using System.arraycopy():
public Payroll(Payroll obj) {
this.employeeId = new int[obj.employeeId.length];
System.arraycopy(obj.employeeId, 0, this.employeeId, 0, obj.employeeId.length);
...

multiple prints for each input. Why?

Each time I run this code it gets to where it asks for student id and it prints out the student id part and the homework part. Why? I am trying to do get a string for name, id, homework, lab, exam, discussion, and project then in another class I am splitting the homework, lab, and exam strings into arrays then parsing those arrays into doubles. After I parse them I total them in another method and add the totals with project and discussion to get a total score.
import java.util.Scanner;
import java.io.*;
public class GradeApplication_Kurth {
public static void main(String[] args) throws IOException
{
Student_Kurth one;
int choice;
boolean test = true;
do
{
Scanner keyboard = new Scanner(System.in);
PrintWriter outputFile = new PrintWriter("gradeReport.txt");
System.out.println("Please select an option: \n1. Single Student Grading \n2. Class Grades \n3. Exit");
choice = keyboard.nextInt();
switch (choice)
{
case 1 :
System.out.println("Please enter your Student name: ");
String name = keyboard.next();
System.out.println("Please enter you Student ID: ");
String id = keyboard.nextLine();
System.out.println("Please enter the 10 homework grades seperated by a space: ");
String homework = keyboard.next();
System.out.println("Please enter the 6 lab grades seperated by a space: ");
String lab = keyboard.nextLine();
System.out.println("Please enter the 3 exam grades seperated by a space: ");
String exam = keyboard.nextLine();
System.out.println("Please enter the discussion grade: ");
double discussion = keyboard.nextDouble();
System.out.println("Please enter the project grade: ");
double project = keyboard.nextDouble();
one = new Student_Kurth(name, id, homework, lab, exam, discussion, project);
outputFile.println(one.toFile());
System.out.println(one);
break;
case 2 :
File myFile = new File("gradeReport.txt");
Scanner inputFile = new Scanner(myFile);
while(inputFile.hasNext())
{
String str = inputFile.nextLine();
System.out.println("\n" + str);
}
break;
case 3 :
test = false;
keyboard.close();
outputFile.close();
System.exit(0);
}
} while (test = true);
}
}
second class
public class Student_Kurth
{
public String homework;
public String name;
public String id;
public String lab;
public String exam;
public double project;
public double discussion;
public double[] hw = new double[10];
public double[] lb = new double[6];
public double[] ex = new double[3];
public final double MAX = 680;
public double percentage;
public String letterGrade;
public Student_Kurth()
{
homework = null;
name = null;
id = null;
lab = null;
exam = null;
project = 0;
discussion = 0;
}
public Student_Kurth(String homework, String name, String id, String lab, String exam, double project, double discussion)
{
this.homework = homework;
this.name = name;
this.id = id;
this.lab = lab;
this.exam = exam;
this.project = project;
this.discussion = discussion;
}
public void Homework(String homework)
{
String delims = " ";
String[] tokens = this.homework.split(delims);
int tokenCount = tokens.length;
for(int i = 0; i < tokenCount; i++)
{
hw[i] = Double.parseDouble(tokens[i]);
}
}
public void Lab(String lab)
{
String delims = " ";
String[] tokens = this.lab.split(delims);
int tokenCount = tokens.length;
for(int i = 0; i < tokenCount; i++)
{
lb[i] = Double.parseDouble(tokens[i]);
}
}
public void Exam(String exam)
{
String delims = " ";
String[] tokens = this.exam.split(delims);
int tokenCount = tokens.length;
for(int i = 0; i < tokenCount; i++)
{
ex[i] = Double.parseDouble(tokens[i]);
}
}
public double getHomeworkTotal(double[] hw)
{
double hwTotal = 0;
for(int i = 0; i < hw.length; i++)
{
hwTotal += hw[i];
}
return hwTotal;
}
public double getLabTotal(double[] lb)
{
double lbTotal = 0;
for(int i = 0; i < lb.length; i++)
{
lbTotal += lb[i];
}
return lbTotal;
}
public double getExamTotal(double[] ex)
{
double exTotal = 0;
for(int i = 0; i < ex.length; i++)
{
exTotal += ex[i];
}
return exTotal;
}
public double getTotalScores(double getExamTotal, double getLabTotal, double getHomeworkTotal)
{
return getExamTotal + getLabTotal + getHomeworkTotal + this.project + this.discussion;
}
public double getPercentage(double getTotalScores)
{
return 100 * getTotalScores / MAX;
}
public String getLetterGrade(double getPercentage)
{
if(getPercentage > 60)
{
if(getPercentage > 70)
{
if(getPercentage > 80)
{
if(getPercentage > 90)
{
return "A";
}
else
{
return "B";
}
}
else
{
return "C";
}
}
else
{
return "D";
}
}
else
{
return "F";
}
}
public void getLetter(String getLetterGrade)
{
letterGrade = getLetterGrade;
}
public void getPercent(double getPercentage)
{
percentage = getPercentage;
}
public String toFile()
{
String str;
str = " " + name + " - " + id + " - " + percentage + " - " + letterGrade;
return str;
}
public String toString()
{
String str;
str = "Student name: " + name + "\nStudent ID: " + id + "\nTotal Score: " + getTotalScores(getExamTotal(ex), getLabTotal(lb), getHomeworkTotal(hw)) +
"\nMax Scores: " + MAX + "Percentage: " + percentage + "Grade: " + letterGrade;
return str;
}
}

At the end of the switch, you have
while ( test = true)
You probably want to change that to
while ( test == true)
Also, take these lines out of the loop:
Scanner keyboard = new Scanner(System.in);
PrintWriter outputFile = new PrintWriter("gradeReport.txt");

In addition to Ermir's answer, this line won't capture all the grades:
System.out.println("Please enter the 10 homework grades seperated by a space: ");
String homework = keyboard.next();
Keyboard.next only reads until the next delimiter token, so if you want to capture 10 grades separated by spaces you need capture the whole line, like:
System.out.println("Please enter the 10 homework grades separated by a space: ");
String homework = keyboard.nextLine();