如何大写字符串的每个替代字符？

Question

假设有一个字符串“johngoestoschool”，它应该成为“JoHnGoEsToScHoOl”，并且如果在它之间存在特殊字符，则应该忽略它，例如给定字符串“jo $％@＃hn^goe！st＃ OS & CH∞）l”的答案应该是 “乔$％@＃Hn的^ g 则oE！ST＃OS & CH OO）L”

从this答案，我们以迭代，我们可以做：

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

为什么我们不能打印“我”她的价值她è？ 当我们做i.customPlaygroundQuickLook类型int 0到int4。

所以我的想法是

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

请帮助

Answer 1

这应该解决您的功能，最困难的部分是刚刚检查的天气特点是字母或不使用inout和替换范围将提供更好性能：

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 
}