Converting List[List[Int]] to Set[Int] in Scala

Question

Is it possible to convert a List containing inner lists of type Int to Set[Int] in Scala?

For example, is the following conversion possible:

-> List(List(0), List(1), List(2)) to Set(0, 1, 2)

If yes, can it be explained?

Akos Krivachy · Accepted Answer · 2013-11-24 21:13:45Z

13

First you need to flatten the list then convert it to a set:

List(List(0), List(1), List(2)).flatten.toSet
res0: Set[Int] = Set(0, 1, 2)

So what does flatten do? When you have multiple nested collections inside of each other it reduces the nesting by one level. This is applicable to anything that's Traversable like for an example Options also.

answered Nov 24, 2013 at 21:13

Akos Krivachy

4,96625 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

brandbir Over a year ago

Exactly, I came up with the same solution. Thanks very much

Collectives™ on Stack Overflow

Converting List[List[Int]] to Set[Int] in Scala

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related