ios - 如何大写字符串的每个备用字符？

Question

可以说有一个字符串“johngoestoschool”，它应该变成“JoHnGoEsToScHoOl”，并且如果它们之间有特殊字符，则应该忽略它，例如给定字符串“jo $％@＃hn ^ goe!st＃os＆choo)l”的。答案应为“Jo $％@＃Hn ^ GoE!sT＃oS＆cHoO)l”

从this答案，我们为了迭代我们可以做:

let s = "alpha"
for i in s.characters.indices[s.startIndex..<s.endIndex]
{
    print(s[i])
}

为什么我们不能在此处打印“i”的值？
当我们执行i.customPlaygroundQuickLook时，它将int 0键入为int4。

所以我的想法是

if (i.customPlaygroundQuickLook == 3) {
        s.characters.currentindex = capitalized
}

请帮助

Answer 1

这应该可以解决您的功能，最困难的部分只是检查天气字符是否为字母，使用inout和replace range可以提供更好的性能:

func altCaptalized(string: String) -> String {
    var stringAr = string.characters.map({ String($0) }) // Convert string to characters array and mapped it to become array of single letter strings
    var numOfLetters = 0

    // Convert string to array of unicode scalar character to compare in CharacterSet
    for (i,uni) in string.unicodeScalars.enumerated() {
        //Check if the scalar character is in letter character set
        if CharacterSet.letters.contains(uni) { 
            if numOfLetters % 2 == 0 {
                stringAr[i] = stringAr[i].uppercased() //Replace lowercased letter with uppercased
            }
            numOfLetters += 1
        }
    }

    return stringAr.joined() //Combine all the single letter strings in the array into one string
}