"Functional" way to get all list items inside a list

Asked Jun 19 '17 at 21:31

Active Jun 19 '17 at 21:34

Viewed 99 times

Basically, I have this piece of code:

    final List<Article> articles = new ArrayList<>();

    feeds.forEach(feed -> articles.addAll(feed.getArticles()));

    return articles;

Is there a way to make it any more Java 8-functional? To eliminate the additional variable and make this entire block into a single return statement?

asked Jun 19 '17 at 21:31

Cube.

4

`return feeds.stream().flatMap(feed -> feed.getArticles().stream()).collect(toList());` – Louis Wasserman Jun 19 '17 at 21:34
Do you mean something like that:`feeds.stream().map(Feed::getArticles).collect(Collectors.toList());` That is assuming that `feeds` is a collections of `Feed` objects. – Michael Jun 19 '17 at 21:37
@Michael It returns `List>`. – Jun 19 '17 at 21:41
@saka1029 Right, missed the `.addAll` – Michael Jun 19 '17 at 21:43
@LouisWasserman Yes. Please add it as an answer below so that it can be more visible. :) – Cube. Jun 19 '17 at 21:45
@Cube., the question has been marked as a duplicate; I can't add it as an answer, and it's not clear that I should when the duplicates are valid. – Louis Wasserman Jun 19 '17 at 21:46

0 Answers0