Changing Course Challenge Task 2 of 3. Looking for a reference point.

public Map<String, Video> videosByTitle(Course course) {
    // List<Video> videoList = course.getVideos(); Classic case of DRY...
    Map<String, Video> videoMap = new TreeMap<>();
    for (Video video : course.getVideos()) {
      videoMap.put(video.getTitle(), video);
    }
    return videoMap;
  }

This is the code i got to pass challenge 2. I think I am still a little confused on the use of the for loop.

I understand the code, just about every line, except the use of the for loop, most specifically the parameters that are passed into the for loop. Maybe that is why I was having such an issue with this challenge.

The for-each loop works like this.... for each thing in things, or for every single item in the grouping of items, do these lines of code.

So course.getVideos() returns a list of videos, and each time the code in between the { run each video is in context, when the code finishes, the next one shows up. It loops as many times as there are things, and works on one at a time.

That make sense?

If I am understanding this correctly, the map that is created, videoMap, the for-each loop is placing (.put()) each video into the map by title (the key) and the video location (the value), and sorting them alphabetically because we declared it to be a TreeMap.

If I were to recall your explanation of a HashMap, a dictionary.

In this case it would be "Video Title" - "Location of the video". Does it specifically call a database? Such as a text file you had demonstrated for the Karaoke Machine, specifically in Custom Serialization.

Also thank you for providing me the assistance here Craig.

Awesome, you got it! It doesn't do any storing. The Map is simply being returned from the method.

Indeed it is basically a dictionary of title to video (where video is an object reference), and TreeMap sorts keys by natural sort order, which is alphabetical. Nailed it!