Java Java Data Structures Efficiency! Changing Course

Damjan Vlaic
Damjan Vlaic
19,241 Points

---JAVA---

can someone help me with this please, the task says:

Finally, lets finish that final method fixVideoTitle. I will pass in the course, the current title, and the title I want to change it to. Hey you should totally use that videosByTitle map to help you find the video!

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.Map;
import java.util.HashMap;

public class QuickFix {

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

  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {

  }

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

}

1 Answer

Marko Medic
Marko Medic
5,656 Points

Hi, you should use the method videosByTitle in this one to get the map of videos and then get the video you want to change with oldTitle as the key and call the setTitle(newTitle) method to change it.

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