Scala - convert List of Lists into a single List: List[List[A]] to List[A]

Question

What's the best way to convert a List of Lists in scala (2.9)?

I have a list:

List[List[A]]

which I want to convert into

List[A]

How can that be achieved recursively? Or is there any other better way?

question from:https://stackoverflow.com/questions/12600863/scala-convert-list-of-lists-into-a-single-list-listlista-to-lista

Answer 1

List has the flatten method. Why not use it?

List(List(1,2), List(3,4)).flatten
> List(1,2,3,4)