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Java Java Objects Delivering the MVP Forum

Jose Torres
Jose Torres
Courses Plus Student 2,493 Points

Can anyone help me finish putting it together, cant seem to figure out how to get it to run.

After you uncomment the code in Main.java and Forum.java, fix the code as described in the comments of Main.java. The code in main is attempting to use the code you just fixed.

public class Forum {
  private String topic;

  // TODO: add a constructor that accepts a topic and sets the private field topic

  public String getTopic() {
    return topic;
  public forum (private String topic) {
    mTopic = topic;

  /* Uncomment this when you are prompted to do so
  public void addPost(ForumPost post) {
    System.out.printf("A new post in %s topic from %s %s about %s is available",

public class User {
  private String firstName;
  private String lastName;

  // TODO: add private fields for firstName and lastName

  public User(String firstName, String lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
    // TODO: set and add the private fields

  public String getFirstName() {
    return firstName;
  public String getLastName() {
    return lastName;

  // TODO: add getters for firstName and lastName

public class ForumPost {
  private User author;
  private String title;
  private String description;

  private forumPost(User author, String title, String description) {
    this.author = author;
    this.title = title;
    this.description = description;

  // TODO: add a constructor that accepts the author, title and description

  public User getAuthor() {
    return author;

  public String getTitle() {
    return title;

  public String getDescription() {
    return description;
public class Main {

  public static void main(String[] args) {
    System.out.println("Beginning forum example");
    if (args.length < 2) {
      System.out.println("Usage: java Main <first name> <last name>");
      System.err.println("<first name> and <last name> are required");

    Forum forum = new Forum("Java");
    // TODO: pass in the first name and last name that are in the args parameter
    String firstName = args[0];
    String lastName = args[1];
    User author = new User(firstName, lastName); //<----- all cruicial points marked with comments
    // TODO: initialize the forum post with the user created above and a title and description of your choice

    ForumPost post = new ForumPost(author, "Programming is awesome", "Cuz it makes us create new stuff");

4 Answers

Kyle Shifflett
Kyle Shifflett
8,496 Points

the f in ForumPost constructor is lowerCase, and its private so thats gonna be the only class that can call the ForumPost constructor. Also, the f in your public Forum() constructor is lowercase, && the parameters it's passing in has an unnecessary private modifier.

I might be missing what the assignment requires, but couldn't hurt to try.

You're correct.

Looks like you changed the constructor. Capitalise Forum and remove the private from the parameter:

  public Forum (String topic) {
    mTopic = topic;

Bed time here... 1am.


As Kyle said, change ForumPost back to capitals too.

Have you uncommented the code in Forum.java?

You can also just pass in args[0] and args[1] in the User constructor without creating new variables for them. So:

User author = new User(args[0], args[1]);

Your method should also work but doing stuff unnecessarily is generally frowned upon. :wink:


Jose Torres
Jose Torres
Courses Plus Student 2,493 Points

Yes sir, i just did still not running im getting this error,

./Forum.java:9: error: invalid method declaration; return type required public forum (String topic) { ^ ./ForumPost.java:6: error: invalid method declaration; return type required public forumPost(User author, String title, String description) { ^ Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. 2 errors

Jose Torres
Jose Torres
Courses Plus Student 2,493 Points

Got it running now! thanks for all your help Steve & kyle !

No problem! :+1: :wink: