Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Java Java Objects Delivering the MVP Forum

Christopher Mlalazi
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Christopher Mlalazi
Front End Web Development Techdegree Graduate 17,305 Points

Am stuck: Are you sure you used the arguments passed in from the main method in Main.java? args[0] is the firstName and

Am on 4/4 of this exercises and I have tried everything on Main.java and failed and keep getting this error message: Are you sure you used the arguments passed in from the main method in Main.java? args[0] is the firstName and args[1] should be the last name?

Where am I going wrong? I thought I was on the right track!

Forum.java
public class Forum {
  private String topic;

  // TODO: add a constructor that accepts a topic and sets the private field topic
  Forum(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",
            topic,
            post.getAuthor().getFirstName(),
            post.getAuthor().getLastName(),
            post.getTitle()
    );
  }


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

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

  }

  // TODO: add getters for firstName and lastName
  public String getFirstName(){
    return firstName;
  }
  public String getLastName(){
    return lastName;
  }

}
ForumPost.java
public class ForumPost {
  private User author;
  private String title;
  private String description;

  // TODO: add a constructor that accepts the author, title and description
  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;
  }
}
Main.java
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");
      System.exit(1);
    }

    Forum forum = new Forum("Java");
    // TODO: pass in the first name and last name that are in the args parameter
   User author = new User(args[0], args[1]);
    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost(author, "Programming", "Fundamentals");
    forum.addPost(post);
  }

}

2 Answers

Hi Christopher,

The original user constructor looked like this:

public User(String firstName, String lastName) {

But you changed the parameter names to mFirstName and mLastName

This means the name fields aren't getting updated with what is passed in.