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Java Java Data Structures - Retired Efficiency! Changing Course

Joseph Kawa
Joseph Kawa
1,807 Points

Help with code challenge 3 of 3

I'm having issues with this problem and am not sure which steps to take. I created a new TreeMap in the fixVideo method but not sure how to change the video titles. I tried to remove the course first by calling the remove method on treemaps and then add the course + the title but that didn't work either. Please help!

com/example/model/Course.java
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;
  }

}
com/example/model/Video.java
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;
  }

}
QuickFix.java
import com.example.model.Course;
import com.example.model.Video;

import java.util.TreeMap;
import java.util.Map;

public class QuickFix {

  public void addForgottenVideo(Course course) {
    // TODO(1):  Create a new video called "The Beginning Bits"
Video newVideo = new Video("The Beginning Bits");
    // TODO(2):  Add the newly created video to the course videos as the second video.
  course.getVideos().add(1, newVideo);



  }

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
  Map<String, Video> byTitle = new TreeMap<>();
    byTitle.remove(videosByTitle(course));
    byTitle.put(course.getName(), newTitle);


  }

  public Map<String, Video> videosByTitle(Course course) {
  Map<String, Video> byTitle = new TreeMap<String, Video>();
   for (Video video : course.getVideos()) {
            byTitle.put(video.getTitle(), video);
        }
    return byTitle;
  }

}

1 Answer

Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher

The method videosByTitle returns a Map where the key is the title. If you can get the video out by the oldTitle then you just need to set that video's title using the newTitle.

Let me know if that hint does it for you ;)