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Java Java Objects (Retired) Delivering the MVP Wrapping up

William Richert
William Richert
6,418 Points
Posted by William Richert
William Richert
6,418 Points

Stumped on passing final code challenge

I cannot see what I am missing here, suffice to say there are error messages pointing me to the parameters that I am passing into the new User constructor call.

 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
    String firstName = args[0];
    String lastName = args[1];
    User author = new User(String firstName, String lastName);
    ForumPost post = new ForumPost(User author, String "Java Rocks!", String "Onwards!");
    forum.addPost(post);
  }
}
ForumPost.java 
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;
  }

  // TODO: We need to expose the description
  public String getDescription() {
    return mDescription;  
  }


}
User.java 
public class User {
    private String mFirstName;
    private String mLastName;

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

  public String getFirstName() {
    return this.mFirstName;  
  }

  public String getLastName() {
    return this.mLastName;  
  }
}
Forum.java 
public class Forum {
  private String mTopic;

  public String getTopic() {
      return mTopic;
  }

  public Forum (String topic) {
      mTopic = topic;
  } 

  public void addPost(ForumPost post) {
      System.out.printf("New post from %s %s about %s.\n",
                         post.getAuthor().getFirstName(),
                         post.getAuthor().getLastName(),
                         post.getTitle());
  }
}
Example.java 
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
    String firstName = args[0];
    String lastName = args[1];
    User author = new User(String firstName, String lastName);
    ForumPost post = new ForumPost(User author, String "Java Rocks!", String "Onwards!");
    forum.addPost(post);
  }
}

1 Answer

Ken Alger
STAFF
Ken Alger
Treehouse Teacher
Ken Alger
Ken Alger
Treehouse Teacher

William;

In Example.java you have multiple errors, although similar and easy to fix.

In these two lines...

Example_Snippet.java 
    User author = new User(String firstName, String lastName);
    ForumPost post = new ForumPost(User author, String "Java Rocks!", String "Onwards!");

You don't need to pass in they data types here, just the variable names. If, for example firstName is not of type String Java will let you know. Removing the type declarations will get your code to pass.

Happy coding,
Ken

William Richert
William Richert
6,418 Points
William Richert
William Richert
6,418 Points

Thank you very much. I had a real misconception about adding the datatypes into method and constructor calls.

Ken Alger
Ken Alger
Treehouse Teacher
Ken Alger
Ken Alger
Treehouse Teacher

William;

Yes, when you call methods, or create new objects you typically don't want to include the types. There are cases in which you would but one of the things that I personally like about Java is that it is strongly typed and knows that when you create a new User, in this case, that you need to pass in a String and String. If you attempt to pass in something else, an int, for example, it won't like that.

Happy coding,
Ken