Welcome to the Treehouse Community
Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.
Looking to learn something new?
Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.
Start your free trialPrabhat Kumar
Courses Plus Student 320 Pointsnot able to update key in hashmap
I am not able to update key in HashMap,please suggest
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.HashMap;
import java.util.List;
import java.util.Iterator;
import java.util.Map.Entry;
public class QuickFix {
public void addForgottenVideo(Course course) {
// TODO(1): Create a new video called "The Beginning Bits"
Video vd = new Video("The Beginning Bits");
// TODO(2): Add the newly created video to the course videos as the second video.
course.getVideos().add(1,vd);
}
public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
Map<String,Video> map = new HashMap<String,Video>();
map =videosByTitle(course);
Iterator it = map.entrySet().iterator();
Video vd = null;
while(it.hasNext()){
Entry item =(Entry) it.next();
if(item.getKey().equals(oldTitle) ){
vd =(Video) item.getValue();
it.remove();
}
}
map.put(newTitle,vd);
}
public Map<String, Video> videosByTitle(Course course) {
Map<String,Video> map = new HashMap<String,Video>();
List<Video> videoList = course.getVideos();
String title = null;
for(Video vd : videoList){
title = vd.getTitle();
map.put(title,vd);
}
return map;
}
}
1 Answer
Umesh Ravji
42,386 PointsHi Prabhat, I think you may have misunderstood the question. The fixVideoTitle()
method simply requires you to find the video object
that has the title
of oldTitle
and update the title
to be newTitle
.
public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
Video video = this.videosByTitle(course).get(oldTitle); // obtain video using previously created method
if (video != null) {
video.setTitle(newTitle);
}
}
Prabhat Kumar
Courses Plus Student 320 PointsPrabhat Kumar
Courses Plus Student 320 PointsThanks Umesh :)