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Java Java Objects Delivering the MVP Forum

Java Objects Forum step four

"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."

Can anyone give me some tips with this one please? It's had me completely stumped for a while now and with this version of the course being relatively new, its difficult to find relevant information. Thanks!

public class Forum {
  private String topic;

  // TODO: add a constructor that accepts a topic and sets the private field topic
public topic(String topic){
this.topic = topic;

  public String getTopic() {
    return topic;

  public void addPost(ForumPost post) {
    System.out.printf("A new post in %s topic from %s %s about %s is available",

public class User {
  // TODO: add private fields for firstName and lastName
  private String firstName;
  private String lastName;

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


  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;

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

  public ForumPost(User author, String title, String description){
   this.author = author;
    this.title = title;
    this.description = 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
    User author = new User();
    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost();



1 Answer

Anders Björkland
Anders Björkland
7,481 Points

Hi Micah,
You've come along pretty well. All that is left is that you pass the right arguments to each constructor in the Main-class. It might be new to you, but you've got som arguments to work with in the main-method of main, as it is passed an array of strings called args. args is supposed to contain strings representing first name and last name. Access each string with args[0] and args[1]. Use this as arguments for the User-constructor. Then remember to use the right arguments for the ForumPost-constructor (it takes a User, a String, and another String).

I hope this will help you.
Good luck!