How to create all possible combinations from the elements of a list?

Question

I have the following list:

List(a, b, c, d, e)

How to create all possible combinations from the above list?

I expect something like:

Answer 1

val xs = List( 'a', 'b' , 'c' , 'd' , 'e' )
(1 to xs.length flatMap (x => xs.combinations(x))) map ( x => x.mkString(""))

This should give you all the combination concatenated by empty String.