Check if a character is lowerCase or upperCase

Question

I am trying to make a program that stores a string in a variable called input.

With this input variable, I am then trying to convert it to an array, and then test with a for loop whether each character in the array is lowerCase or not. How can I achieve this?

Here is how far I have gotten:

var input = "The quick BroWn fOX jumpS Over tHe lazY DOg"

var inputArray = Array(input)

for character in inputArray {
    /*

    if character is lower case {

        make it uppercase

    } else {

        make it lowercase

    }

    */
}

Answer 1

Swift 3

static func isLowercase(string: String) -> Bool {
    let set = CharacterSet.lowercaseLetters

    if let scala = UnicodeScalar(string) {
      return set.contains(scala)
    } else {
      return false
    }
  }

Answer 2

 var input = "The quick BroWn fOX jumpS Over tHe lazY DOg"

 var inputArray = Array(input)

 for character in inputArray {

 var strLower = "[a-z]";

 var strChar = NSString(format: "%c",character )
 let strTest = NSPredicate(format:"SELF MATCHES %@", strLower );
 if strTest .evaluateWithObject(strChar)
 {
   // lower character
 }
 else
 {
   // upper character
 }
}

Answer 3

Swift 4:

var input = "The quick BroWn fOX jumpS Over tHe lazY DOg"
let uppers = CharacterSet.uppercaseLetters
let lowers = CharacterSet.lowercaseLetters
input.unicodeScalars.forEach {
    if uppers.contains($0) {
        print("upper: \($0)")
    } else if lowers.contains($0) {
        print("lower: \($0)")
    }
}