在Swift中查找字符串中的空格數

Question

要查找Swift中字符串中的空格數，需要調用哪種方法。然後我想通過這樣的數字循環：

@IBOutlet weak var stack: UILabel! 

@IBOutlet weak var plus: UIButton! 

@IBAction func sum(sender: AnyObject) { 
    var stackTitle = stack.text 
    var numberOfSpaces = stackTitle!.CanICallSomethingHereToHelp:) 
    var i:Int 
    for i = 1; i < numberOfSpaces; ++i{ 
     operate(plus) 
    } 
} 

謝謝！

Answer 1

let str = "Hello, playground. Hello, playground !!!" 
let spaceCount = str.characters.filter{$0 == " "}.count 
print(spaceCount) // 4 

Answer 2

let title = "A sample string to test with." 
let count = title.componentsSeparatedByString(" ").count - 1 
print(count) // 5 

Answer 3

的另一種方法可能是由以下函數的實現：

func nbSpacesIn(_ word: String) -> Int { 
return String(word.unicodeScalars.filter({$0.value == 32})).count}