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

scala list recursion flatten
A Far picture A Far · Sep 26, 2012 · Viewed 31.8k times · Source

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?

Answer

Jan picture Jan · Sep 26, 2012

List has the flatten method. Why not use it?

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

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