After you uncomment the code in Main.java and Forum.java, fix the code as described in the comments of Main.java.

Hi Bhawani,

Let's start at the beginning - you'd said you were at stage 4 which was what I answered in the previous post.

The first task, as in the previous post, is to create a constructor for Forum. The question is Add a constructor that accepts a String named topic to Forum.java. Initialize the private field topic in the constructor to the value passed in.

A constructor for the Forum class will be called the same as the class. It will be public. The question tells us it takes a String parameter so that it can set the private field called topic with the value that is passed in. Use the keyword this to identify that you're using the member variable called topic that is a member of this instance.

That all look like:

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

Your code had the constructor set to private and called it forum not Forum (capital F is required).

Next ... In User.java, add private fields to store firstName and lastName, and initialize them in the provided constructor. Add public getters for firstName and lastName. This is quite a big task!

Start with the member variables. They are private and both are of type String. Their names are given. Add:

  private String firstName;
  private String lastName;

at the start of the User class where the comments tell you to. Now we need to initialize them in the constructor. This is the same as above. Set the this member variable to be the value passed into the constructor:

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

Next, we need to add getter methods for these two member variables. These methods will be public and will return the private member variable. Call them getFirstName and getLastName. They return a data type of String.

That looks like:

  // TODO: add getters for firstName and lastName
  public String getFirstName(){
    return firstName;
  }
  public String getLastName(){
    return lastName;
  }

Next ... Add a constructor to ForumPost which accepts a User named author, a String named title, and another String named description. Initialize the corresponding private fields.

That's simple. Create a constructor to populate the three member variables that are already in the class. These are:

  private User author;
  private String title;
  private String description;

Again, the constructor is called the same as the class and is public. Start with:

public ForumPost(){

}

Then, pass in the three required parameters and set them inside the method; we've done this before, as above:

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

Now, uncomment the two blocks of code in Forum and Main - make sure you uncomment the whole of each block. Then work through the comments in Main. The first is: // TODO: pass in the first name and last name that are in the args parameter. I answered this in the other post too. The main method is called with an array of strings as its argument. The first two elements of this array are the first and last names. Access the array with square brackets; the array is called args. So, the first name is stored in args[0] and the last name is in args[1].

To complete the author instance would look like:

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

The next Todo is // TODO: initialize the forum post with the user created above and a title and description of your choice. The constructor for ForumPost takes three parameters; we know this - we wrote it!! We've created an instance of User, above. It is called author then you want to pass in two strings of your choice. I'll keep it simple:

    // TODO: initialize the forum post with the user created above and a title and description of your choice
    ForumPost post = new ForumPost(author, "Title", "Description");

That's it.

I hope that helps.

Steve.