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Java Java Objects (Retired) Delivering the MVP Wrapping up

Posted by bighnaraj panda
bighnaraj panda
Courses Plus Student 1,054 Points

Hi, how do we pass an argument through command line ?

I am getting an error "I expected to see the arguments i passed"

ForumPost.java 
public class ForumPost {
  private User mAuthor;
  private String mTitle;
  private String mDescription;

  public ForumPost(User author, String title, String description){

    mAuthor = author;
    mTitle= title;
    mDescription = description;

  }

  public User getAuthor() {
    return mAuthor;
  }

  public String getTitle() {
    return mTitle;
  }

  // TODO: We need to expose the description

  public String getDescription() {
    return mDescription;
  }

}
User.java 
public class User {

  private String mFirstName;
  private String mLastName;

  public User(String firstName, String lastName) {
    // TODO:  Set the private fields here


      mFirstName = firstName;
      mLastName = lastName;

  }
  public String getFirstName() {
    return mFirstName;
  }

   public String getLastName() {
    return mLastName;
  }

}
Forum.java 
public class Forum {
  private String mTopic;

  public Forum(String Topic){
    mTopic= Topic;

  }

  public String getTopic() {
      return mTopic;
  }

  public void addPost(ForumPost post) {
       //When all is ready uncomment this...
      System.out.printf("New post from %s %s about %s.\n",
                         post.getAuthor().getFirstName(),
                         post.getAuthor().getLastName(),
                         post.getTitle());

  }
}
Example.java 
public class Example {

  public static void main(String[] args) {
    System.out.println("Starting forum example...");
    if (args.length < 2) {
       System.out.println("first and last name are required. eg:  java Example Craig Dennis");
    }
    Forum forum = new Forum("JAVA");
     //Take the first two elements passed args
     User author = new User("James","Camerron");

     //Add the author, title and descriptionint
     ForumPost post = new ForumPost(author,"feels","great");
     forum.addPost(post);
  }
}

1 Answer

jcorum
jcorum
71,830 Points
jcorum
jcorum
71,830 Points

Arguments can be passed in at runtime, via the main method's String[] args parameter. Each IDE does it a bit differently. For this challenge you just need to pass the first two to the new User(). The assumption here is that args[0] is the first name and args[1] is the last name:

public class Example {

  public static void main(String[] args) {
    System.out.println("Starting forum example...");
    if (args.length < 2) {
       System.out.println("first and last name are required. eg:  java Example Craig Dennis");
    }
    Forum forum = new Forum("Java");
    // Take the first two elements passed args
    User author = new User(args[0], args[1]);  //how to use args 
    // Add the author, title and description
    ForumPost post = new ForumPost(author, "title", "description");
    forum.addPost(post);
  }
}