Swift Anagram checker

I am attempting to build an anagram checker for swift. This is my code. In case you don't know an anagram checker checks if two strings have the same characters in them but, order does not matter.

func checkForAnagram(#firstString: String, #secondString: String) -> Bool {
    var firstStringArray: [Character] = []
    var secondStringArray: [Character] = []
    /* if case matters delete the next four lines
    and make sure your variables are not constants */
    var first = firstString
    var second = secondString
    first = first.lowercaseString
    second = second.lowercaseString
    for charactersOne in first {
        firstStringArray += [charactersOne]
    }
    for charactersTwo in second {
        secondStringArray += [charactersTwo]
    }
    if firstStringArray.count != secondStringArray.count {
        return false
    } else {
        for elements in firstStringArray {
            if secondStringArray.contains(elements){
                return true
            } else {
                return false
            }
        }

}
}


var a = "Hello"
var b = "oellh"
var c = "World"
checkForAnagram(firstString: a, secondString: b)

I am getting an error message of.

'[Character]' does not have a member 'contains'

You should try

func checkForAnagram(firstString firstString: String, secondString: String) -> Bool {
    return firstString.lowercaseString.characters.sort() == secondString.lowercaseString.characters.sort()
}