What is the best way to determine if a string contains a character from a set in Swift

Question

I need to determine if a string contains any of the characters from a custom set that I have defined.

I see from this post that you can use rangeOfString to determine

Answer 1

From Swift 1.2 you can do that using Set

var str = "Hello, World!"
let charset: Set = ["e", "n"]

charset.isSubsetOf(str)     // `true` if `str` contains all characters in `charset`
charset.isDisjointWith(str) // `true` if `str` does not contains any characters in `charset`
charset.intersect(str)      // set of characters both `str` and `charset` contains.

Swift 3 or later

let isSubset = charset.isSubset(of: str)        // `true` if `str` contains all characters in `charset`
let isDisjoint = charset.isDisjoint(with: str)  // `true` if `str` does not contains any characters in `charset`
let intersection = charset.intersection(str)    // set of characters both `str` and `charset` contains.
print(intersection.count)   // 1