Ios 辅音和元音

我是Swift的新手，有人能解释一下为什么我总是遇到这个问题吗。我使用的是Xcode 6.4，但这里有一个问题，我希望我能解决它，但我需要我的函数来接收大字符串，然后返回元组（numowels，numConsonants） 计算以辅音/元音开头的单词数 返回元组并打印函数调用的结果。 我不需要它计算字符，只需要每个单词的第一个字符。我创建了一个for循环，它将所有内容切换为小写。但现在我被卡住了

func count(string: String) -> (Vowels:Int, Consonants:Int) {
    var Vowels = 0, Consonants = 0
    for character in string {
        switch String(character).lowercaseString {
            case "a","e","i","o","u":
              ++Vowels
            case "b","c","d","e","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z":
            ++Consonants
        default: break
        }

    }
    return (Vowels, Consonants)
}

---

问题在于您为方法选择的名称。试试除计数之外的任何名字，你应该会没事的

编辑/更新：Swift 4

func countCharacteres(_ string: String) -> (vowels: Int, consonants: Int) {
    var vowels = 0, consonants = 0
    for character in string {
        switch String(character).lowercased() {
        case "a","e","i","o","u":
            vowels += 1
        case "b","c","d","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z":
            consonants += 1
        default:
            break
        }
    }
    return (vowels, consonants)
}

---

---

如果只想计算每个单词的第一个字母，则需要将字符串拆分为一个单词数组，并提取每个第一个字母的小写字母，如下所示：

extension StringProtocol where Index == String.Index {
    var range: Range<Index> { return startIndex..<endIndex }
    var words: [String] {
        var words: [String] = []
        enumerateSubstrings(in: range, options: .byWords) { word, _, _, _ in words.append(word!) }
        return words
    }
}
extension StringProtocol  where Index == String.Index {
    var firstCharacterCount: (vowels: Int, consonants: Int) {
        var vowels = 0, consonants = 0
        for first in words.compactMap({$0.lowercased().first}) {
            switch first {
            case "a","e","i","o","u":
                vowels += 1
            case "b","c","d","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z":
                consonants += 1
            default: break
            }
        }
        return (vowels, consonants)
    }
}

---

请注意，扩展名应放在项目内的新Swift文件中。

如果使用Swift 2：

换一行就行了

for character in string {

到

这样就行了

count("hello") // (.0 2, .1 3)

---

另一种选择是使用正则表达式检索每个单词的第一个字母。

\b

选项用于查找单词边界，

\w

是单个单词字符。因此，一旦您避开后斜杠，

\\b\\w

将捕获紧跟在单词边界之后的第一个字母（也称为每个单词的第一个字母）：

--

如果要处理重音字符（如“étude”），可能需要先删除这些变音符号：

func countLetters(string: String) -> (vowels: Int, consonants: Int) {
    let convertedString = NSMutableString(string: string)
    CFStringTransform(convertedString, nil, kCFStringTransformStripCombiningMarks, Boolean(0))

    var vowels = 0, consonants = 0
    let regex = NSRegularExpression(pattern: "\\b\\w", options: nil, error: nil)
    regex?.enumerateMatchesInString(convertedString as String, options: nil, range: NSMakeRange(0, convertedString.length)) { matches, flags, stop in
        switch convertedString.substringWithRange(matches.range).lowercaseString {
        case "a","e","i","o","u":
            ++vowels
        case "b","c","d","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z":
            ++consonants
        default: break
        }
    }
    return (vowels, consonants)
}

---

您是否在XCode 7 beta 5中使用swift 2？我在XCode中使用swift从目前提供的答案来看，我认为没有人正确理解您的问题。请澄清。请给出一个输入示例，您从输出中得到了什么，以及您对输出的期望值。您能澄清一下您到底想做什么吗？@JetLagg请将这些澄清整合到原始问题中。单击问题下方的“编辑”，然后更新原始问题。我读到他的问题时说“我正在统计所有字母的数量，我只想要每个单词的第一个字母。”我想你回答的是另一个问题。@Rob你是对的。但他仍然需要为他的方法选择另一个名称。也许这是他的主要问题别误会我：我同意他最好改名。这与问题无关，伊姆霍。事实上没有@LeoDabus，看我的答案。但问题仍然不够清楚。谢谢大家，这就是我需要将字符串和单词数组@LyndseyScott，LeoDabusThis分解成的内容。这是正确的，如果他想将其转换为Swift 2，他会这样做。但我认为这不是当前的问题。

for character in string.characters {

count("hello") // (.0 2, .1 3)

func countLetters(string: String) -> (vowels: Int, consonants: Int) {
    var vowels = 0, consonants = 0
    let regex = NSRegularExpression(pattern: "\\b\\w", options: nil, error: nil)
    regex?.enumerateMatchesInString(string, options: nil, range: NSMakeRange(0, count(string))) { matches, flags, stop in
        switch (string as NSString).substringWithRange(matches.range).lowercaseString {
        case "a","e","i","o","u":
            ++vowels
        case "b","c","d","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z":
            ++consonants
        default: break
        }
    }
    return (vowels, consonants)
}

func countLetters(string: String) -> (vowels: Int, consonants: Int) {
    let convertedString = NSMutableString(string: string)
    CFStringTransform(convertedString, nil, kCFStringTransformStripCombiningMarks, Boolean(0))

    var vowels = 0, consonants = 0
    let regex = NSRegularExpression(pattern: "\\b\\w", options: nil, error: nil)
    regex?.enumerateMatchesInString(convertedString as String, options: nil, range: NSMakeRange(0, convertedString.length)) { matches, flags, stop in
        switch convertedString.substringWithRange(matches.range).lowercaseString {
        case "a","e","i","o","u":
            ++vowels
        case "b","c","d","f","g","h","j","k","l","m","n","p","q","r","s","t","v","w","x","y","z":
            ++consonants
        default: break
        }
    }
    return (vowels, consonants)
}