In Scala how do I remove duplicates from a list?

Question

Suppose I have

val dirty = List(\"a\", \"b\", \"a\", \"c\")

Is there a list operation that returns \"a\", \"b\", \"c\"

Answer 1

Before using Kitpon's solution, think about using a Set rather than a List, it ensures each element is unique.

As most list operations (foreach, map, filter, ...) are the same for sets and lists, changing collection could be very easy in the code.