Java Java Objects Delivering the MVP Forum

Rafał Stasiak
Rafał Stasiak
2,602 Points

All time syntax error

Can someone help me with fixing my code? When I try to recheck my work I got errors. What is wrong?

Forum.java
public class Forum {
  private String topic;

  // TODO: add a constructor that accepts a topic and sets the private field topic
public topicName (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 {
  private String lastName;
  private String firstName;

  public User(String firstName, String lastName) {
    this.firstName = firstName;
    this.lastName = lastName;
  }

  public String getFirstName() {
    return firstName;
  }

   public String getLastName() {
    return lastName;
  }
  // TODO: add getters for firstName and 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.title = title;
  this.description = description;
  this.author = author; 
  }
  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("John","Brown");
    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost(author, "NewWorld","Nature");
    forum.addPost(post);
  }

}

1 Answer

Daniel Turato
PRO
Daniel Turato
Java Web Development Techdegree Graduate 30,086 Points

There's two things you are doing wrong. 1st thing is that your constructor for Forum needs to be the same name as the class like so:

public Forum (String topic) {
 this.topic = topic;
} 

The 2nd thing you are doing wrong is that you need to pass in the first two elements of the args array into the author user object like so:

User author = new User(args[0], args[1]);

Once you do these things, your code should work

Rafał Stasiak
Rafał Stasiak
2,602 Points

Thank you Daniel it is working now.

Could you explain: Why I need to code like you said:

User author = new User(args[0], args[1]); instead of ("first name", "last name");

In User.java i coded as below:

public User(String firstName, String lastName)

Daniel Turato
Daniel Turato
Java Web Development Techdegree Graduate 30,086 Points

Well, the constructor for User requires two strings which have two local names as firstName and lastName. Therefore, in theory, you can pass in any two valid strings when instantiating a new User object. But the challenge requires you to pass in the first two elements in the args array, therefore that's why you have to use args[0] and args[1].