Scala Seq case match

Question

I have a Sequence that I would like to case match. The question that I have is quite simple:

Are the following two cases the same?

case x :: Nil =>
case x :: xs  =>

Can I instead just have

case Nil =>
case x :: xs  =>

How would the case x :: Nil be handled? Would it also match the case Nil?

Answer 1

No, they are not the same.

case x :: Nil matches a list with exactly one element.

case x :: xs matches a list that has at least one element.

case Nil matches an empty list