How can I check if a string contains letters in Swift? [duplicate]

Question

I'm trying to check whether a specific string contains letters or not.

So far I've come across NSCharacterSet.letterCharacterSet() as a set of letters, but I'm having trouble checking whether a character in that set is in the given string. When I use this code, I get an error stating:

'Character' is not convertible to 'unichar'

For the following code:

for chr in input{     if letterSet.characterIsMember(chr){         return "Woah, chill out!"     } } 

Answer 1

You can use NSCharacterSet in the following way :

let letters = NSCharacterSet.letters  let phrase = "Test case" let range = phrase.rangeOfCharacter(from: characterSet)  // range will be nil if no letters is found if let test = range {     println("letters found") } else {    println("letters not found") } 

Or you can do this too :

func containsOnlyLetters(input: String) -> Bool {    for chr in input {       if (!(chr >= "a" && chr <= "z") && !(chr >= "A" && chr <= "Z") ) {          return false       }    }    return true } 

In Swift 2:

func containsOnlyLetters(input: String) -> Bool {    for chr in input.characters {       if (!(chr >= "a" && chr <= "z") && !(chr >= "A" && chr <= "Z") ) {          return false       }    }    return true } 

It's up to you, choose a way. I hope this help you.