Why is the + operator for List deprecated in Scala?
Class Listdoes not offer an append operation because the time it takes to append to a list grows linearly with the size of the list, whereas prepending with :: takes constant time. Your options if you want to build a list by appending elements is to prepend them, then when you’re done call reverse; or use a ListBuffer, a mutable list that does offer an append operation, and when you’re done call toList.
