i need help with task 4 of 4 with forum.

Question

please help

Forum.java

public class Forum {
  private String topic;
private String firstName;
  private String lastName; 

  public String getTopic() {
    return topic;
  }

public Forum(String topic) {
this.topic = 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.\n",
            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 firstName, String lastName) {
    // TODO: set and add the private fields
this.firstName = firstName;
this.firstName = lastName;

  }

  // TODO: add getters for firstName and lastName

  public String getFirstName() {
    return this.firstName;

}

 public String getLastName() {
   return this.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
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;
  }
}

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, "title of the damn thing", "About some jibberish like C++");
    forum.addPost(post);
  }

}

Answer 1 · 2018-01-04T05:03:03Z

January 4, 2018 5:03am

The constructor in the User.java file initializes the firstName variable twice. That could be the problem.

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

  }

Answer 2 · 2018-01-04T05:07:52Z

January 4, 2018 5:07am

Here's what I found (short answer)

Look at your variable assignments in User.java

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

firstName is being first being assigned the value of firstName (Bob) and then the value of lastName(McBobberson ).

Because lastName is never assigned a value, the author's name ends up being "McBobberson" null instead of "Bob" "Mc Bobberson"

Which explains why the preview output showed...

A new post in Java topic from McBobberson null about title of the damn thing is available

... when I first ran your code in the challenge.

Once that was fixed, the code passed the challenge.

I'll be completely honest this didn't jump out at me right away like it should have. If you are interested in how I figured it out using strategically placed System.out.println commands read on.

I started by figuring out what values I should be expecting by printing the args to the preview:

Main.java

 public static void main(String[] args) {
    System.out.println("Beginning forum example:");
    System.out.println("Arg Values: " + args[0] + ":" + args[1]);

Beginning forum example:

Bob:McBobberson

Then made sure those were the values being passed into User.java

User.java

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

    System.out.println("Author Created: " + firstName + ":" + lastName);

  }

Author Created: Bob:McBobberson

The variables being passed in from args[0] and args[1] are correct . So far so good.

On to the next place we reference the author

ForumPost.java

  public ForumPost(User author, String title, String description) {
  this.author = author;
  this.title = title;
  this.description = description;

  System.out.println("Post Created: " + author.getFirstName() + ":" + author.getLastName());

Post Created: McBobberson: null

Umm.... that's not right. We passed in the right values. So something is going wrong when the User is being created. Looking more closely at User.java I saw that firstName is being first being assigned the value of firstName (Bob) and then the value of lastName(McBobberson ). Also that lastName is never getting assigned a value.

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Ronald Greer

Ronald Greer

i need help with task 4 of 4 with forum.

Brian DuPont

Brian DuPont

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Brian Bochicchio