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Java Java Data Structures Exploring the Java Collection Framework Sets

A little help needed

I'm working on this and I feel like I've implemented the solution correctly. No compile errors, but the automated check doesn't seem to be seeing my method. The error I'm getting is "Did you add a method getAllAuthors() to the blog class?

package com.example;

import java.util.List;
import java.util.Set;
import java.util.TreeSet;

public class Blog {
  List<BlogPost> mPosts;

  public Blog(List<BlogPost> posts) {
    mPosts = posts;

  public List<BlogPost> getPosts() {
    return mPosts;
  public Set<String> getAllAuthors(List<BlogPost> blogPosts)
    Set<String> authorList = new TreeSet();
    for (BlogPost blogPost : blogPosts)
    return authorList;

1 Answer

Jason Wiram
Jason Wiram
42,184 Points

You are very close. You don't need to pass any parameters to the getAllAuthors() method. The Blog class constructor takes 'List<BlogPost> blogPosts' as a parameter and initializes it to the field mPosts. That is the list you will iterate over in your function. Make sense?