How to check whether a string only contains certain characters, say "a" and "b" in Scala?
I found several resources online, they are using regex.
For Scala, most of them talked about the findAllIn or findFirstIn function. But I would like to have something that returns true or false.
>Solution :
val s: String = ???
s.forall("ab".contains)
forall checks whether a condition is true for all elements of a collection. So in this case it checks whether a condition is true for each character in s.
contains checks whether a string contains a character, so "ab".contains(x) checks whether x is either ‘a’ or ‘b’.