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Java Java Objects Delivering the MVP Forum

Yang Liu
Yang Liu
2,708 Points

Challenge Task 4 of 4 User author format, what to do with the User type input for ForumPost post method

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");

  User author = new User("Yang", "Liu"); 

  ForumPost post = new ForumPost("Yang Liu","Java", "Programer" );
  forum.addPost(post);
  }

}

/* Uncomment this when prompted*/




  //TODO: pass in the first name and last name that are in the args parameter




// TODO: initialize the forum post with the user created above and a title and description of your choice

./Main.java:14: error: incompatible types: String cannot be converted to User ForumPost post = new ForumPost("Yang Liu","Java", "Programer" ); ^ ./Main.java:15: error: cannot find symbol forum.addPost(post); ^ symbol: method addPost(ForumPost) location: variable forum of type Forum ./ForumPost.java:9: error: incompatible types: String cannot be converted to User this.author=title; ^ ./ForumPost.java:10: error: incompatible types: String cannot be converted to User this.author=description; ^ Note: JavaTester.java uses unchecked or unsafe operations. Note: Recompile with -Xlint:unchecked for details. Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output 4 errors

Forum.java
public class Forum {
  private String topic;

   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 {
  // 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.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.author=title; 
this.author=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"); 

      User author = new User("Yang", "Liu"); 

      ForumPost post = new ForumPost("Yang Liu","Java", "Programer" );
      forum.addPost(post);
      }

}

    /* Uncomment this when prompted*/




      //TODO: pass in the first name and last name that are in the args parameter




    // TODO: initialize the forum post with the user created above and a title and description of your choice

1 Answer

Kayondo Martin
Kayondo Martin
7,481 Points

According to the challenge, you were supposed to pass in the firtname and last name that are in the args parameter, not hard coded strings. in other words, look at sample code below...

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

ForumPost post = new ForumPost(author,"Java","Programmer");

then go to the Forum class and uncomment the addPost method

hope it helps.