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Java Java Objects Delivering the MVP Forum

melissa zhang
melissa zhang
760 Points
Posted by melissa zhang
melissa zhang
760 Points

Add public getters for firstName and lastName. Please help to code this.

Hi, can anyone show me how to code this question. Many thanks.

Forum.java 
public class Forum {
  private String topic;

  // TODO: add a constructor that accepts a topic and sets the private field topic
  private Forum(String topic){
    topic=field;
  }

  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
    firstName =field;
    lastName =field;

  }

  // TODO: add getters for firstName and lastName
  public getFirstName(){

    private String field;
    return firstName;

  }
  public getLastName(){
    lastName = field;
    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 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();
    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost();
    forum.addPost(post);

// */
  }

}

4 Answers

Dino Šporer
Dino Šporer
5,430 Points
Dino Šporer
Dino Šporer
5,430 Points

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

2)private String firstName; private String lastName;

this.firstName = firstName; this.lastName = lastName;

public String getFirstName() { return firstName; }

public String getLastName() { return lastName; }

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

4) Forum forum = new Forum("Java");
User author = new User(args[0], args[1]); ForumPost post = new ForumPost(author, "new title", "no description"); forum.addPost(post);

melissa zhang
melissa zhang
760 Points
melissa zhang
melissa zhang
760 Points

thank you so so much!!!!!

Alexander La Bianca
Alexander La Bianca
15,959 Points
Alexander La Bianca
Alexander La Bianca
15,959 Points

Hi,

In your constructor you need to set the private fields firstName and lastName to whatever is passed into the constructor. Like this:

public User(String firstName, String LastName) {
  //set the private field firstName to the firstName parameter
  this.firstName = firstName;
 //set the private field lastName to the lastName parameter
this.lastName = lastName
}

Note that the keyword 'this' is only used because the parameter and the private fields have the same name. If your parameters were something like pFirstName and pLastName you would not have to use the keyword 'this'.

Next your public getters should just return whatever the value of the private fields are.

public String getFirstName() {
  return firstName;
}

You do not need to create a extra variables like you did. Simply return the value for firstName. So when you actually use the User class it could be something like this:

User myUser = new User("Alex", "La Bianca");
String lastNameofMyUser = myUser.getLastName(); //returns "La Bianca"
String firstNameofMyUser = myUser.getFirstName();  //returns "Alex"
melissa zhang
melissa zhang
760 Points
melissa zhang
melissa zhang
760 Points

You are a STAR! Thanks a lot.

Dino Šporer
Dino Šporer
5,430 Points
Dino Šporer
Dino Šporer
5,430 Points

dino.sporer88@gmail.com here is my mail, so you can write or something :D