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Java Java Data Structures Efficiency! Changing Course

David Moody
David Moody
19,302 Points

Need Help With Logic Behind This Challenge

I cannot quite figure out with this challenge the logic behind how to add the video to the courses. The compiler keeps telling me that I am mix-matching types. How do I get a video added to the list of videos without mixmatching types?

Should I do course = new Course(title, video)? How do I think about where the video is supposed to go so that I can map it out and insert the video correctly?

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.ArrayList;
import java.util.List;
import java.util.Map;

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.

  }

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

  }

  public Map<String, Video> videosByTitle(Course course) {
    return null;
  }

}

1 Answer

Daniel Vargas
Daniel Vargas
29,184 Points

Hello,

You should create a List<Video> and then call the getVideos method from Course.java, after that just add the new Video to the List:

import com.example.model.Course;
import com.example.model.Video;

import java.util.Map;
import java.util.List;

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.
    List<Video> listOfVideos=course.getVideos();
    listOfVideos.add(1,video);
  }

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

  }

  public Map<String, Video> videosByTitle(Course course) {
    return null;
  }

}

I hope this can help you.