如何将每个句子中的第一个单词大写 Swift

Question

考虑到用户区域设置，我怎样才能将段落中每个句子的第一个单词大写？我想要实现的是无论句子中的大小写如何，每个单词的第一个字母都是大写的，其余的都是小写的。我只能做一个句子，首先将所有内容都转换为小写，然后获取第一个字母并转为大写，最后将它们加在一起。我的问题与不同，因为我不想将每个单词都大写。我只想将每个句子的第一个单词大写。 capitalizedString转

"this is first sentence. this is second sentence."

至

"This Is First Sentence. This Is Second Sentence."

我要的是

"This is first sentence. This is second sentence."

我的问题也不同于 Capitalise first letter of every sentence 因为@rintaro 的代码不适用于我下面的示例。它保持原始文本中的大写字母完整无缺。使用@rintaro 的代码；

之前

"someSentenceWith UTF text İŞğĞ. anotherSentenceğüÜğ"

之后

"SomeSentenceWith UTF text İŞğĞ. AnotherSentenceğüÜğ."

我想达到的目标，

"Somesentencewith utf text işğğ. Anothersentenceğüüğ."

我下面的代码只能进行部分转换。

var description = "someSentenceWith UTF text İŞğĞ. anotherSentenceğüÜğ"
description = description.lowercaseStringWithLocale(NSLocale.currentLocale())
let first = description.startIndex
let rest = advance(first,1)..<description.endIndex
let capitalised = description[first...first].uppercaseStringWithLocale(NSLocale.currentLocale()) + description[rest]

如果您能仔细阅读我的问题，我将不胜感激，因为这是我第三次编辑问题。如果我不能问清楚，我真的很抱歉，因为我不是母语人士。所以即使@rintaro 回答了类似的问题，他的回答并没有解决我的问题。 @martin-r 提出了一个 Objective-C 的答案，这又不能解决我遇到的问题。还有另一个用户 eric something 也提出了另一个答案，但后来被删除了。我只是不明白为什么几个人提出了不同的答案，但没有回答我的问题。

Answer 1

尝试：

let str = "someSentenceWith UTF text İŞğĞ. anotherSentenceğüÜğ"

var result = ""
str.uppercaseString.enumerateSubstringsInRange(indices(str), options: .BySentences) { (sub, _, _, _)  in
    result += sub[sub.startIndex ... sub.startIndex]
    result += sub[sub.startIndex.successor() ..< sub.endIndex].lowercaseString
}

println(result) // -> "Somesentencewith utf text i̇şğğ. Anothersentenceğüüğ"

添加：Swift2

let str = "someSentenceWith UTF text İŞğĞ. anotherSentenceğüÜğ"

var result = ""
str.uppercaseString.enumerateSubstringsInRange(str.characters.indices, options: .BySentences) { (sub, _, _, _)  in
    result += String(sub!.characters.prefix(1))
    result += String(sub!.characters.dropFirst(1)).lowercaseString
}

print(result)

Answer 2

您可以使用正则表达式来实现这一点。我将此函数添加为 String 扩展，因此将来调用起来很简单：

extension String {

    func toUppercaseAtSentenceBoundary() -> String {
        var string = self.lowercaseString

        var capacity = string.utf16Count
        var mutable = NSMutableString(capacity: capacity)
        mutable.appendString(string)

        var error: NSError?

        if let regex = NSRegularExpression(
            pattern: "(?:^|\b\.[ ]*)(\p{Ll})",
            options: NSRegularExpressionOptions.AnchorsMatchLines,
            error: &error
            ) {

            if let results = regex.matchesInString(
                string,
                options: NSMatchingOptions.allZeros,
                range: NSMakeRange(0, capacity)
                ) as? [NSTextCheckingResult] {

                    for result in results {
                        let numRanges = result.numberOfRanges
                        if numRanges >= 1 {
                            for i in 1..<numRanges {
                                let range = result.rangeAtIndex(i)
                                let substring = mutable.substringWithRange(range)
                                mutable.replaceCharactersInRange(range, withString: substring.uppercaseString)
                            }
                        }
                    }
            }
        }

        return mutable
    }
}

var string = "someSentenceWith UTF text İŞğĞ. anotherSentenceğüÜğ.".toUppercaseAtSentenceBoundary()

Answer 3

更新@rintaro 的代码 Swift 3:

let str = "someSentenceWith UTF text İŞğĞ. anotherSentenceğüÜğ"

var result = ""
str.uppercased().enumerateSubstrings(in: str.startIndex..<str.endIndex, options: .bySentences) { (sub, _, _, _)  in
    result += String(sub!.characters.prefix(1))
    result += String(sub!.characters.dropFirst(1)).lowercased()
}

print(result)

Answer 4

我根据@Katy的代码

在Swift3中写了这个扩展

extension String {

func toUppercaseAtSentenceBoundary() -> String {

 var result = ""
    self.uppercased().enumerateSubstrings(in: self.startIndex..<self.endIndex, options: .bySentences) { (sub, _, _, _)  in
        result += String(sub!.characters.prefix(1))
        result += String(sub!.characters.dropFirst(1)).lowercased()
    }

    return result as String 
  }
}

使用方法：

let string = "This is First sentence. This is second Sentence.".toUppercaseAtSentenceBoundary() 
print(string) /* Output: "This is first sentence. This is second sentence." */

如何将每个句子中的第一个单词大写 Swift

How to capitalize first word in every sentence with Swift

swift

nsstring