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Java Java Objects Delivering the MVP Forum

salhin langhi
salhin langhi
2,198 Points
Posted by salhin langhi
salhin langhi
2,198 Points

Don't understand the compiler error

Do not understand why there is an error cannot find symbol. According to the compiler User = author; is incorrect, do not understand why since this code was sufficient for task 3. I think I might be doing something obviously wrong but I do not know what.

Forum.java 
public class Forum {
  private String topic;

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

  // TODO: add a constructor that accepts a topic and sets the private field topic

  public String getTopic() {
    return 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",
            topic,
            post.getAuthor().getFirstName(),
            post.getAuthor().getLastName(),
            post.getTitle()
    );
  }


}
User.java 
public class User {

  private String firstName;
  private String lastName;
  // TODO: add private fields for firstName and lastName

  public User(String firstName, String lastName) {

    this.firstName = firstName;
    this.lastName = lastName;
      // TODO: set and add the private fields

  }

  // 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

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

    // Uncomment this when prompted
     Forum forum = new Forum("Java");  
    // TODO: pass in the first name and last name that are in the args parameter

    User Author = new User("rhino", "emily");
    // TODO: initialize the forum post with the user created above and a title and description of your choic
    ForumPost post = new ForumPost(Author, "Mr", "big");
    forum.addPost(post);


  }

}

3 Answers

Daniel Szepanski
PLUS
Daniel Szepanski
Courses Plus Student 5,098 Points
Daniel Szepanski
Daniel Szepanski
Courses Plus Student 5,098 Points

Hi, i think your problem is the Main.java, try to change User Author = new User("rhino", "emily") ---->User author = new User(args[0], args[1]) it should work, cause your variable is Uppercase and you have to use the args parameter as in the comment above.

Hope this will help you.

Steve Hunter
Steve Hunter
57,712 Points
Steve Hunter
Steve Hunter
57,712 Points

Hiya,

The args[0] and args[1] thing has been covered in Daniel's answer.

One other thing; your User constructor isn't correct. This:

  public ForumPost (User author, String title, String description){
    User = author; // <- change this 
    this.title = title;
    this.description = description;
  }

You should handle the User instance the same as the other two. So change your line to:

this.author = author

You send the User object from the other file into this constructor, just like you're sending the strings in.

I hope that makes sense.

Steve.

salhin langhi
salhin langhi
2,198 Points
salhin langhi
salhin langhi
2,198 Points

Thank you very much for your help Daniel and Steve it works fine now