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Java Java Data Structures - Retired Exploring the Java Collection Framework Sets

Posted by chevano gordon
chevano gordon
3,399 Points

heres how far i got

still not knowing what to do

2 Answers

Steven Donovan
Steven Donovan
13,281 Points 
package com.example;

import java.util.List;
import java.util.Set;
import java.util.SortedSet;
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() {
    SortedSet<String> authors = new TreeSet<>();
    for (BlogPost post : mPosts) {
      authors.add(post.getAuthor());
    }
    return authors;
  }
}
Steven Donovan
Steven Donovan
13,281 Points

A Set is a unique collection of Objects. A TreeSet is an ordered collection (it implements the Set interface). So just adding Strings to a TreeSet will order them alphabetically.