Bummer, are you sure you updated the videos title?

Okay wait, now I'm confused I got the method for converting it properly to title, but how do I fix the videosByTitle method to let it go through?

The key is video.getTitle and the value is just video.

Congrats on completing the course Rob! Sorry for the rough last one ;)

Oh man, that worked. I finally got that method to work at 3 am last night, and never looked back it once it worked. but you're right. This did fix It, I was really starting to hit my head on the desk against this one.

Thank you Craig and James

Glad you were able to get it in the end.

But I thought you will be pulling the value out rather than the key (oldTitle) by using the 'get' method on it ?

https://docs.oracle.com/javase/7/docs/api/java/util/Map.html

"get(Object key) Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key."

My line of thought was to get the value out of the map and replace the map with the newTItle and old value.

 if(videoTitlesMap.containsKey(oldTitle)){
      // The Title is there, lets get the value
            Video videoValue = videoTitlesMap.get(oldTitle);
            //Use the value to set the new title
            //videoValue.setTitle(newTitle);
          videoTitlesMap.put(newTitle,videoValue);


    }

But if I do it this way, I would negate the fact of using setTitle. Is there the above correct and challenge is expecting us to use the setTitle and thus giving us an error? Or am I wrong in my line of thoughts?

Remember Edane Barton they are just object references. You don't need to put it back in the map. Just change the title, the one in the map points to the same place!

Awesome post J.D!

Would you mind making this a post of its own, so it doesn't get lost? Object references was exactly what I was trying to nail down in this challenge. Awesome explanation!

Thanks!

Hey J.D. , anyone can correct me if I am wrong but in order for an object to not be a reference and actually be a new object is by using the "new" keyword. Using the new Keyword will always create an object.

I tried this thing but it is still giving me an compioler error saying the course is already defined "public Map videosByTitle(Course course) {".

Hey Thanks.. I think that more or less gave me better understand, I tried to change the code to

public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
    Map<String, Video> newVideoMap = videosByTitle(course);
    Video video = newVideoMap.get(oldTitle);
    if (newVideoMap.containsKey(oldTitle)) {
      newVideoMap.put(newTitle, video.setTitle(newTitle));
      newVideoMap.remove(oldTitle);
    }

But it's still not working, any further advice on this?

Sorry to pester, was up too late trying to sort this out, definitely appreciate the help.

Don't worry about setting the map, they are object references. Just set the title and you are done!

James White,

For your future reference, whenever there is a question asked via the "Get Help" button on a challenge, such as this one, there is a green "View Challenge" button on the top right hand corner of the question that you can click on it to go back to the challenge. Hope that helps you! :)

Okay it's fixed now, step 2 will no longer pass with a bad mapping. Thanks for catching that!

Thanks Craig, sorry for the trouble it caused.

I tried everything in the forum but I am still getting the same error

Hey Roshan Kashif !

Can you add a new post with your code please?

Thanks Rob, but it's now giving me a compiler error on video

Can you please copy your error?

Thanks.

This should work fine...remember they are object references.

videoTitleMap.put(video.getTitle(), video);

videoList is an instance variable and is only in the method's scope.

You actually don't need it in videosByTitle you could just do this:

for (Video video : course.getVideos()) {

That make more sense?

ok, but i still feel like i am missing the core concept of part 2 of the challenge. 1) i dont understand why i need the count piece. shouldnt it be more of a check if its there if not add otherwise skip? 2) i understand what you are saying with replacing it. by why if i already defined it in addForgottenVideo cant i use videoList again without redefining it in videsByTitle? that is a concept i struggle with because i defined it in a public class so i thought i could access it as long as i was in that same file?

Thanks for such a prompt reply.

You don't need the count piece. Just loop the videos, for each video set the title for the key and the video for the value. You are riffing on code you don't need, don't let it confuse you ;)

Secondly...so, see how it is defined in the method, you can tell because the Type is specified there, that makes it a local variable, it is not a field on the class. These methods we are working on here are made to work with many different Course objects, see how the course is passed in. If you did indeed make a class field that stored the videoList as an instance variable it would be wrong for each different course that was passed into the method.

So the local variable is created so you can use it. Like I said though, in my last comment, you actually don't need it.

ok i understand what you mean about it being a local variable. It makes sense that if its defined beneath a piece like that then its only in use for that section. I have to set it as a member variable to make it available for all my sections.

now my struggle is a compiler error when i try to reference the videosByTitle map from task 2: java:17: error: cannot find symbol if (videosByTitle.containsKey(oldTitle)) {

My logic is using the previously built map i should be able to check for the oldTitle, add the newTitle (key) with the oldTitle's (value) then remove the old title.

 public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
      if (videosByTitle.containsKey(oldTitle)) {
          videosByTitle.put(newTitle, videosByTitle.get(oldTitle));
            videosByTitle.remove(oldTitle);
  }

Thanks so much for your help, the videos are great but sometimes i feel like i am just typing what you type without getting comprehension so its nice to have the challenges test my comprehension and its nice to have the forums to help me grasp the concepts which i failed to grasp.

Craig thanks for the help i was able to get challenge 3. I figured instead of calling videosByTitle i could just make that tree map a protected variable for the class. So i moved it up and got rid of the compiler error. 1) I tried to do the same with the videoList variable that we discussed previously in the post but it created a compiler error on not recognizing the symbol so i punted on that one. 2) i dont understand why its cleaner to use the setTitle method instead of just saying this? java videosByTitle.put(newTitle, videosByTitle.get(oldTitle));

Below is my end code result as clean as i could get it, but get it i did, thanks for the help really appreciate it.

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

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

public class QuickFix {
  protected Map<String, Video> videoTitleMap = new TreeMap<String, Video>();

    public void addForgottenVideo(Course course) {
   List<Video> videoList = course.getVideos();
    Video video = new Video("The beginning bits");
    videoList.add(1, video);
  } 
  public void fixVideoTitle(Course course, String oldTitle, String newTitle) {
      if (videoTitleMap.containsKey(oldTitle)) {
          Video video = videoTitleMap.get(oldTitle);
            video.setTitle(newTitle);
        videoTitleMap.remove(oldTitle);
    }
  }
  public Map<String, Video> videosByTitle(Course course) {
    //Map<String, Video> videoTitleMap = new TreeMap<String, Video>();
    List<Video> videoList = course.getVideos();
    for (Video video : videoList) {
     videoTitleMap.put(video.getTitle(), video);
       } 
return videoTitleMap;
  }
}

Yeah the map is being built is wrong. It's all the videos titles pointing to a single video, instead of the actual video. Right? videoList.get(1) will insert the 2nd video in the list for each video title. He just wants video there for the value.

Edit***

nevermind I found the error,

 videoMap.put(video.getTitle, video);

The parenthesis are missing in video.getTitle();