Question

所以我陷入了编码挑战，我几乎也知道了答案。而且我认为我必须在Swift 4中使用subString调用来获得它100％。我想要反转字符串中的每个OTHER字，但忽略或保留标点符号在其原始位置（索引）。

var sample = "lets start. And not worry about proper sentences."

func reverseString(inputString: String) -> String {
    let oldSentence = sample.components(separatedBy: " ")
    var newSentence = ""
    for index in 0...oldSentence.count - 1 {
        let word = oldSentence[index]
        if newSentence != "" {
            newSentence += " "
        }
        if index % 2 == 1 {
            let reverseWord = String(word.reversed())
            newSentence += reverseWord
        } else {
            newSentence += word
        }
    }
    return newSentence
}

reverseString(inputString: sample)

这将是预期的输出。

"lets trats. And ton worry tuoba proper secnetnes."

注意标点符号没有反转。

Answer 1

您不应该使用components(separatedBy: )在字词中分割字符串。请参阅this article了解原因。使用enumerateSubstrings并传入相应的选项：

func reverseString(inputString: String) -> String {
    var index = 1
    var newSentence = inputString
    inputString.enumerateSubstrings(in: inputString.startIndex..., options: .byWords) { substr, range, _, stop in
        guard let substr = substr else { return }
        if index % 2 == 0 {
            newSentence = newSentence.replacingCharacters(in: range, with: String(substr.reversed()))
        }
        index += 1
    }
    return newSentence
}

print(reverseString(inputString: "lets start. And not worry about proper sentences."))
// lets trats. And ton worry tuoba proper secnetnes.

print(reverseString(inputString: "I think, therefore I'm"))
// I kniht, therefore m'I

反转字符串中的每个其他单词，保持标点符号Swift

1 个答案: