Java Error - Missing method body or declare abstract - java

emphasized textI've been working on this problem for a while and managed to get rid of almost all the errors on this class. This error keeps saying I'm missing method body or declare abstract but I just don't see it. I've managed to complete another class almost similar to this but this one seems to be acting strangely. Can someone please help me out? Thank you if you do.
import java.util.Scanner;
public class HockeyPlayer extends StudentAthlete
{
Scanner keyboard = new Scanner(System.in);
public static void main (String [] args)
{
HockeyPlayer athlete1 = new HockeyPlayer("Dave", 111111, 15, 3.2, 2, 3);
athlete1.writeOutput();
}
private int assist = 0;
private int goal = 0;
public HockeyPlayer()
{
super();
goal = 0;
assist = 0;
}
public int getAssist()
{
return assist;
}
public void setAssist(int newAssist)
{
if (0 >= newAssist)
{
assist = newAssist;
}
else
{
System.out.println("Invalid Assists");
System.out.println("Please enter a valid Assists");
int tempAssist = keyboard.nextInt();
setAssist(tempAssist);
}
}
public int getGoal()
{
return goal;
}
public int setGoal(int newGoal)
{
if (0 >= newGoal)
{
goal = newGoal;
}
else
{
System.out.println("Invalid Goals");
System.out.println("Please enter a valid Goals");
int tempGoal = keyboard.nextInt();
setGoal(tempGoal);
}
}
public HockeyPlayer(String initialName, int initialStudentNumber, int initialJersey, double initialGpa, int initialGoal, int initialAssist)
{
super (initialName, initialStudentNumber,initialJersey, initialGpa);
setGoal(initialGoal);
setAssist(initialAssist);
}
public HockeyPlayer(String initialName, int initialStudentNumber, int initialJersey, double initialGpa)
{
super (initialName, initialStudentNumber, initialJersey, initialGpa);
goal = 0;
assist= 0;
}
public HockeyPlayer(String initialName, int initialStudentNumber)
{
super (initialName, initialStudentNumber);
goal = 0;
assist = 0;
}
public HockeyPlayer(String initialName)
{
super(initialName);
goal = 0;
assist = 0;
}
public void writeOutput(); // THE ERROR OCCURS HERE
{
super.writeOutput();
System.out.println("Goals: " + goal);
system.out.println("Assists: " + assist);
}
}

change
public int setGoal(int newGoal)
to
public void setGoal(int newGoal)
Setter methods usually don't have a return type (and based on the fact that you don't try to return anything, you probably didn't intend it to have an int return type).
Also change
public void writeOutput();
to
public void writeOutput()

Related

Inheritance var java

this is the qa:
Define a class called MoreSpeed which extends the following class, and which provides a new method called incSpeed() which adds 1 to the inherited variable length.
this is my answer:
public class Speed {
private int length = 0;
public int getSpeed () { return length; }
public void setSpeed (int i) {
if (i > 0) {
length = i;
}
}
}
public class MoreSpeed extends Speed {
private int length;
public int incSpeed() {
return length+1;
}}
its says that the syntax is good but the class operation is wrong.
please help me,thanks.
No. You are shadowing the length from Speed. Instead, implement incSpeed with getSpeed() like
public int incSpeed() {
return getSpeed() + 1;
}
If you are supposed to modify it as well then use setSpeed(int) to do so
public int incSpeed() {
int s = getSpeed() + 1;
setSpeed(s);
return s;
}

I'm trying to find the sum of the objects that are defined as numbers

I'm doing an exercise, in which I have to create the method add, however due to p and v being defined as objects, I'm having a hard time figuring out how I can define this method in the syntax I've been given in the exercise (I'm only allowed to change the methods).
I would like to add the two inputs 5 and 17 so that it returns 22. I've done a lot of research into other questions where I've seen them write it as Positiv(p + v) but this doesn't quite work.
public class Positiv {
public static void main(String[] args) {
try {
Positiv p = new Positiv(5);
Positiv v = new Positiv(17);
p.add(v);
System.out.println(p.get());
} catch (Exception e) {
e.printStackTrace();
}
}
private int n;
public Positiv(int n) {
if (n < 0) { throw new IllegalArgumentException("exception");
}
this.n = n;
}
public static Positiv add(Positiv v)
{
return new Positiv(n + v);
}
public int get() {
return n;
}
}
In your add method:
public static Positiv add(Positiv v)
{
return new Positiv(n + v);
}
You return a whole new Positiv object. However (correct me if I'm wrong) it looks as if you just want to add the two n fields. You can do this by adding this.get to v.get:
public void add(Positiv v)
{
this.n += v.get();
}
Which will return 22
Tutorial for this
public class HelloWorld{
public static void main(String []args){
Numbers a = new Numbers(5);
Numbers b = new Numbers(10);
int num1 = a.getN();
int num2 = b.getN();
System.out.println(addTwoNumbers(num1, num2));
}
public static int addTwoNumbers(int a, int b) {
return a + b;
}
}
class Numbers {
private int n;
public Numbers(int n) {
this.n = n;
}
public int getN() {
return n;
}
}

How to pass my object into another objects field?

I am trying to fill UCFCourse courseOne in my constructor with a courses[] object in fillWithCourses().UCFCourse courseOne does populate outside of the constructor but will not go into it.
public class UCFSemester<courses> {
private static UCFCourse courseOne;
private static double totalSemesters;
private static double completionTime;
static boolean fillSemester = true;
public UCFSemester(UCFCourse courseOne, UCFCourse[] coursetwo) {
this.courseOne = courseOne;
}
public static UCFCourse getcourseOne() {
return courseOne;
}
public static void setCoursesone(UCFCourse courses) {
courseOne = courses;
}
public static void fillWithCourses(UCFCourse courses[], int l) {
int x = 0;
while (fillSemester) {
for (int n = 0; n < 5; n++) {
if (x != n && courses[x].getCourseLevel() < courses[n].getCourseLevel()) {
setCoursesone(courses[x]);
}
}
fillSemester = false;
}
}
}
Side question.How can I access this all in a non-static way?I need the entire thing to be non-static but no matter what I do I can't get it.Thanks!
You can simply do it by creating a List like this:
public class UCFSemester {
private List<UCFCourse> courseList = new ArrayList<>();
public UCFCourse getCourse(int index) {
return courseList.get(index);
}
public void addCourses(UCFCourse[] courses) {
for(int x = 0; x < courses.length; x++) {
courseList.add(courses[x]);
}
}
}
Here, I'm assuming that you are passing the UCFCourse[] array with all the course details that are there in that particular semester.
addCourses() function will take this array and then add all the corresponding courses to the List.
getCourse() function will return you any particular course from the List (Using Index). You can also modify the search in any way you want.

Trouble Creating An Array Of Objects in Java

This is my sticking point: I need to create an array of Chair objects with default woodType. I am able to declare the array itself, but obviously all the values are null. When I try to instantiate each Chair object in the array, I get errors. I'm not sure what I am doing wrong when trying to instantiate, please help.
public class PAssign3 {
public static void main(String[] args) {
TableSet set1 = new TableSet();
TableSet set2 = new TableSet(5, 7, 4);
// Chair chr1 = new Chair();//this works properly, setting wood as Oak
// Chair chr2 = new Chair("Pine");//works
}
}
class TableSet {
Table table = new Table();
private int numOfChairs = 2;
//creates an array that can hold "numOfChairs" references to same num of
//chair objects; does not instantiate chair objects!!!
Chair[] chairArr = new Chair[numOfChairs];
//instantiate each chair object for length of array
//this loop does not work; Error: illegal start of type
for (int i = 0; i < numOfChairs.length; i++) {
chairArr[i] = new Chair();
}
public TableSet() {
}
public TableSet(double width, double length, int numOfChairs) {
table = new Table(width, length);
this.numOfChairs = numOfChairs;
chairArr = new Chair[numOfChairs];
//this loop also does not work; Error: int cannot be dereferenced
for (int i = 0; i < numOfChairs.length; i++) {
chairArr[i] = new Chair();
}
}
public void setNumOfChairs(int numOfChairs) {
this.numOfChairs = numOfChairs;
}
public int getNumOfChairs() {
return numOfChairs;
}
public String getChairWoodType() {
return chairArr[0].getWoodType();
}
}
class Table {
private double width = 6;
private double length = 4;
public Table() {
}
public Table(double width, double length) {
this.width = width;
this.length = length;
}
public void setWidth(double width) {
this.width = (width < 0) ? 0 : width;
}
public void setLength(double length) {
this.length = (length < 0) ? 0 : width;
}
public double getWidth() {
return width;
}
public double getLength() {
return length;
}
}
class Chair {
private String woodType = "Oak";
public Chair() {
}
public Chair(String woodType) {
this.woodType = woodType;
}
public void setWoodType(String woodType) {
this.woodType = woodType;
}
public String getWoodType() {
return woodType;
}
}
int is a simple type in Java and does not have any methods or fields. Just omit this .length and the error is gone. It seems to me it already stores the actual number of chairs (2).

Calling variables between different classes through methods

I'm doing an assignment for my computer science class.
I've done quite a bit of the assignment, but I'm having a little bit of trouble pulling the individual variables from the classes. We are just getting into classes and objects and this is our first assignment regarding them so I don't completely understand all of it. So far I've been able to print out the teams, but I haven't been able to pull the individual wins, losses, OTL and OTW so that I can compute whether or not each individual team is a winning team.
What I have done so far is create a class called winningRecord and getPoints, which returns a boolean deciding whether it's a winning team or not. (The formula for a winning team is if the points are > Games Played * 1.5 (as that is an even record).
I don't know how to pull the stats, as it has to be written in the HockeyTeam class. I have set it up so that the constructor sets the variables publicly so that the can be accessed, but as far as accessing them, I'm stumped.
As far as storing them once I am able to access them, would I just make a parallel method that has the points for each team, with just one digit assigned to each bin?
Here is all of the code, thanks for looking.
public class A1Q2fixed {
public static void main(String[] parms) { // main method
processHockeyTeams();
}
/*****************************/
public static void processHockeyTeams() { // processing method
boolean[] winningRecord;
HockeyTeam[] hockeyTeams;
hockeyTeams = createTeams();
printTeams(hockeyTeams);
System.out.print("*********************\n");
printWinningTeams();
winningRecord = HockeyTeam.winningRecord(hockeyTeams);
// printWinningTeams(hockeyTeams);
}
/*********************************/
public static void printTeams(HockeyTeam[] hockeyTeams) {
for (int i = 0; i < hockeyTeams.length; i++) {
System.out.println(hockeyTeams[i]);
}
}
public static void printWinningTeams() {
}
public static HockeyTeam[] createTeams() {
HockeyTeam[] teams;
HockeyTeam team;
int count;
teams = new HockeyTeam[HockeyTeams.getNumberTeams()];
team = HockeyTeams.getTeam();
for (count = 0; (count < teams.length) && (team != null); count++) {
teams[count] = team;
team = HockeyTeams.getTeam();
}
return teams;
}
}
/* hockey team class *******/
class HockeyTeam {
public String name;
public int wins;
public int otw;
public int otl;
public int losses;
public HockeyTeam(String name, int wins, int otw, int otl, int losses) {
this.name = name;
this.wins = wins;
this.otw = otw;
this.otl = otl;
this.losses = losses;
}
public String toString() {
System.out.println(name);
return " W:" + wins + " OTW:" + otw + " OTL:" + otl + " L:" + losses;
}
public static boolean[] winningRecord(HockeyTeam[] hockeyTeam) {
boolean array[] = new boolean[hockeyTeam.length];
String name;
int wins;
int otw;
int otl;
int losses;
for (int i = 0; i < hockeyTeam.length; i++) {
System.out.println(HockeyTeam.name);
}
return array;
}
public static int getPoints() {
int points = 0;
return points;
}
}
/* hockey teams class *******************/
class HockeyTeams {
private static int count = 0;
private static HockeyTeam[] hockeyTeams = {
new HockeyTeam("Canada", 5, 3, 0, 0),
new HockeyTeam("Russia", 5, 1, 1, 2),
new HockeyTeam("Finland", 3, 2, 1, 3),
new HockeyTeam("Sweden", 4, 1, 1, 4),
new HockeyTeam("USA", 1, 2, 2, 3), };
public static int getNumberTeams() {
return hockeyTeams.length;
}
public static HockeyTeam getTeam() {
HockeyTeam hockeyTeam;
hockeyTeam = null;
if (count < hockeyTeams.length) {
hockeyTeam = hockeyTeams[count];
count++;
}
return hockeyTeam;
}
}
Thanks,
Matt.
Sorry but I was only able to understand only a part of your question,from what I understood it seems you are not able to access individual wins, losses, OTL and OTW. I hope this answers your question if not please clarify a bit
To access OTL,OTW have a loop as below:
public class A1Q2fixed
{
public static void main(String[] parms) // main method
{
processHockeyTeams();
}
/*****************************/
public static void processHockeyTeams() // processing method
{
boolean[] winningRecord;
HockeyTeam[] hockeyTeams;
hockeyTeams = createTeams();
printTeams(hockeyTeams);
System.out.print("*********************\n");
printWinningTeams();
winningRecord = HockeyTeam.winningRecord(hockeyTeams);
for(HockeyTeam h:hockeyTeams)
{
System.out.println(h.losses);//To access and print losses
System.out.println(h.otw);//To access and print otw
System.out.println(h.otl);//To access and print otl
}
// printWinningTeams(hockeyTeams);
}
/*********************************/
public static void printTeams(HockeyTeam[] hockeyTeams)
{
for (int i = 0; i < hockeyTeams.length; i++)
{
System.out.println(hockeyTeams[i]);
}
}
public static void printWinningTeams()
{
}
public static HockeyTeam[] createTeams()
{
HockeyTeam[] teams;
HockeyTeam team;
int count;
teams = new HockeyTeam[HockeyTeams.getNumberTeams()];
team = HockeyTeams.getTeam();
for (count=0; (count<teams.length) && (team!=null); count++)
{
teams[count] = team;
team = HockeyTeams.getTeam();
}
return teams;
}
}
Also declare name as Static in HockeyTeam

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