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Java Java Objects (Retired) Delivering the MVP Wrapping up

Saad Ahmed
Saad Ahmed
7,090 Points

Challenge task 4 out of 4

Completely clueless Everytime I try to compile this code it says that expected args must be User, String, String but I can't get the name of the user to be anything but a string.

public class ForumPost {
  private User mAuthor;
  private String mTitle;
  private String mDescription;

  public ForumPost(User author, String title, String description) {
    mAuthor = author;
    mTitle = title;
    mDescription = description;

  public User getAuthor() {
    return mAuthor;

  public String getTitle() {
    return mTitle;

  public String getDescription() {
    return mDescription; 

  // TODO: We need to expose the description
public class User {
  private String mFirstName;
  private String mLastName;

  public User(String firstName, String lastName) {
    // TODO:  Set the private fields here
    mFirstName = firstName;
    mLastName = lastName;

  public String getFirstName() {
   return mFirstName; 

  public String getLastName() {
    return mLastName;
public class Forum {
  private String mTopic;

  public Forum(String topic) {
   mTopic = topic; 

  public String getTopic() {
      return mTopic;

  public void addPost(ForumPost post) {

      System.out.printf("New post from %s %s about %s.\n",

public class Example {

  public static void main(String[] args) {
    System.out.println("Starting forum example...");
    if (args.length < 2) {
       System.out.println("first and last name are required. eg:  java Example Craig Dennis");
     Forum forum = new Forum("Java");
     //Take the first two elements passed args
     User author = new User("Saad", "Ahmed");
     //Add the author, title and description
     ForumPost post = new ForumPost(author.getFirstName(), "a", "a");

2 Answers

You need to take the arguments from the command line, for example: User author = new User(args[indexNumber], args[indexNumber])

and because ForumPost constructor is taking a User object as its first parameter you only pass "author". for the second parameter you should call using your Forum object the respective getter for the topic finally the third parameter is a string so you can just pass any string value, example: "Example".

Hope this help you.


Craig Dennis
Craig Dennis
Treehouse Teacher

Awesome you are super close!

Imagine I ran this to perform my testing:

java Example Bob McBobberson

This test calls the Example main method and passes in 2 arguments, first name and last name. You should use those arguments to create the User object.

The ForumPost constructor takes that User object that you created as it's first parameter.

That make sense?