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Java Java Data Structures Efficiency! Changing Course

stuck on last code challenge course java data structures

i'm stuck on this code challenge it gives me an error saying Bummer! Did you return the Map you built in the videosByTitle method? so i thought to myself and i started to look at my last post and someone posted this so i thought what if i try this

return mContactMethods.get(methodName);

just using that code as an example so how would i edit it to return the hash map i have been stuck on this for a while so any help would be nice.

package com.example.model;

import java.util.List;

public class Course {
  private String mName;
  private List<Video> mVideos; 

  public Course(String name, List<Video> videos) {
    mName = name;
    mVideos = videos;

  public String getName() {
    return mName;

  public List<Video> getVideos() {
    return mVideos;

package com.example.model;

public class Video {
  private String mTitle;

  public Video(String title) {
    mTitle = title;

  public String getTitle() {
    return mTitle;

  public void setTitle(String title) {
    mTitle = title;

import com.example.model.Course;
import com.example.model.Video;
import java.util.*; 
import java.util.Map;

public class QuickFix {

  public void addForgottenVideo(Course course) {
    // TODO(1):  Create a new video called "The Beginning Bits"
    List<Video> videoList = course.getVideos();
    Video video = new Video("The Beginning Bits");

    videoList.add(1, video);

    // TODO(2):  Add the newly created video to the course videos as the second video.


  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
      Map<String, Video> newVideoMap = videosByTitle(course);
    Video video = newVideoMap.get(oldTitle);

  public Map<String, Video> videosByTitle(Course course) {
    return null;// How to return the hash map. 


2 Answers

Craig Dennis
Craig Dennis
Treehouse Teacher

So course has a getVideos method which will give you a list of videos. If you create a HashMap and loop over the videos and use the video.getTitle as the key and video as the value, you'll get it.

This is similar to the Treets by Author HashMap we built.

That help?

Thanks Craig Dennis i passed it and your answer helped.