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Start your free trialHimanshu Shukla
120 Pointscan't find mistake
what am i doing wrong in fixVideoTitle()????
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.Map;
import java.util.TreeMap;
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) {
Map<String,Video> videosByTitle = videosByTitle(course);
Video video = videosByTitle.get(oldTitle);
video.setTitle(newTitle);
}
public Map<String, Video> videosByTitle(Course course) {
Map<String,Video> videosByTitle= new TreeMap<>();
for(Video video : course.getVideos()){
Video videoByTitle = videosByTitle.get(video.getTitle());
if(videoByTitle == null){
videoByTitle = new Video(video.getTitle());
}
videosByTitle.put(video.getTitle(),videoByTitle);
}
return videosByTitle;
}
}
1 Answer
andren
28,558 PointsYour fixVideoTitle
method is actually completely fine, the issue is in the videosByTitle
method you wrote in task 2.
The videosByTitle
method is supposed to generate a map where the keys are video titles and the value is the video itself, your code generates a map where the keys are the video titles but the value is a new video object, not the video object that actually came from the course object.
Since the video values are new objects, changing them will not affect the video
object from the course
object.
The videosByTitle
method is actually meant to look like this:
public Map<String, Video> videosByTitle(Course course) {
Map<String,Video> videosByTitle= new TreeMap<>();
for(Video video : course.getVideos()){
videosByTitle.put(video.getTitle(), video);
}
return videosByTitle;
}
You don't need to do any null checks or create any objects, just populate the map with the video title and object.
If you fix that function in your code like this:
import com.example.model.Course;
import com.example.model.Video;
import java.util.Map;
import java.util.TreeMap;
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) {
Map<String,Video> videosByTitle = videosByTitle(course);
Video video = videosByTitle.get(oldTitle);
video.setTitle(newTitle);
}
public Map<String, Video> videosByTitle(Course course) {
Map<String,Video> videosByTitle= new TreeMap<>();
for(Video video : course.getVideos()){
videosByTitle.put(video.getTitle(), video);
}
return videosByTitle;
}
}
Then your code will work.
Himanshu Shukla
120 PointsHimanshu Shukla
120 PointsThanx mate!!