有什么办法可以替换Swift String上的字符吗？

我正在寻找一种方法来替换Swift中的字符String。

示例：“这是我的字符串”

我想用“ +”替换“”以获取“ This + is + my + string”。

我该如何实现？

此答案已针对Swift 4和5进行了更新。如果您仍在使用Swift 1、2或3，请参阅修订历史记录。

您有两种选择。您可以按照@jaumard的建议进行操作并使用replacingOccurrences()

let aString = "This is my string"
let newString = aString.replacingOccurrences(of: " ", with: "+", options: .literal, range: nil)

就像下面@cprcrack所指出的那样，optionsand range参数是可选的，因此，如果您不想指定字符串比较选项或范围以在其中进行替换，则只需执行以下操作。

let aString = "This is my string"
let newString = aString.replacingOccurrences(of: " ", with: "+")

或者，如果数据采用特定格式，例如您要替换的分隔字符，则可以使用components()将字符串拆分为and数组，然后可以使用join()函数将其与指定的分隔符放回原处。

let toArray = aString.components(separatedBy: " ")
let backToString = toArray.joined(separator: "+")

或者，如果您正在寻找一种不使用NSString API的更快速的解决方案，则可以使用它。

let aString = "Some search text"

let replaced = String(aString.map {
    $0 == " " ? "+" : $0
})

您可以使用此：

let s = "This is my string"
let modified = s.replace(" ", withString:"+")    

如果您在代码中的任何位置添加此扩展方法：

extension String
{
    func replace(target: String, withString: String) -> String
    {
       return self.stringByReplacingOccurrencesOfString(target, withString: withString, options: NSStringCompareOptions.LiteralSearch, range: nil)
    }
}

斯威夫特3：

extension String
{
    func replace(target: String, withString: String) -> String
    {
        return self.replacingOccurrences(of: target, with: withString, options: NSString.CompareOptions.literal, range: nil)
    }
}

Swift 3，Swift 4，Swift 5解决方案

let exampleString = "Example string"

//Solution suggested above in Swift 3.0
let stringToArray = exampleString.components(separatedBy: " ")
let stringFromArray = stringToArray.joined(separator: "+")

//Swiftiest solution
let swiftyString = exampleString.replacingOccurrences(of: " ", with: "+")

您是否测试过：

var test = "This is my string"

let replaced = test.stringByReplacingOccurrencesOfString(" ", withString: "+", options: nil, range: nil)

斯威夫特4：

let abc = "Hello world"

let result = abc.replacingOccurrences(of: " ", with: "_", 
    options: NSString.CompareOptions.literal, range:nil)

print(result :\(result))

输出：

result : Hello_world

我正在使用此扩展名：

extension String {

    func replaceCharacters(characters: String, toSeparator: String) -> String {
        let characterSet = NSCharacterSet(charactersInString: characters)
        let components = self.componentsSeparatedByCharactersInSet(characterSet)
        let result = components.joinWithSeparator("")
        return result
    }

    func wipeCharacters(characters: String) -> String {
        return self.replaceCharacters(characters, toSeparator: "")
    }
}

用法：

let token = "<34353 43434>"
token.replaceCharacters("< >", toString:"+")

与Sunkas类似的Swift 3解决方案：

extension String {
    mutating func replace(_ originalString:String, with newString:String) {
        self = self.replacingOccurrences(of: originalString, with: newString)
    }
}

采用：

var string = "foo!"
string.replace("!", with: "?")
print(string)

输出：

foo?

修改现有可变字符串的类别：

extension String
{
    mutating func replace(originalString:String, withString newString:String)
    {
        let replacedString = self.stringByReplacingOccurrencesOfString(originalString, withString: newString, options: nil, range: nil)
        self = replacedString
    }
}

采用：

name.replace(" ", withString: "+")

基于Ramis的答案的 Swift 3解决方案：

extension String {
    func withReplacedCharacters(_ characters: String, by separator: String) -> String {
        let characterSet = CharacterSet(charactersIn: characters)
        return components(separatedBy: characterSet).joined(separator: separator)
    }
}

根据Swift 3命名约定尝试提供合适的函数名称。

发生在我身上的事情较少，我只想在其中更改（单词或字符） String

所以我用 Dictionary

  extension String{
    func replace(_ dictionary: [String: String]) -> String{
          var result = String()
          var i = -1
          for (of , with): (String, String)in dictionary{
              i += 1
              if i<1{
                  result = self.replacingOccurrences(of: of, with: with)
              }else{
                  result = result.replacingOccurrences(of: of, with: with)
              }
          }
        return result
     }
    }

用法

let mobile = "+1 (800) 444-9999"
let dictionary = ["+": "00", " ": "", "(": "", ")": "", "-": ""]
let mobileResult = mobile.replace(dictionary)
print(mobileResult) // 001800444999

var str = "This is my string"
str = str.replacingOccurrences(of: " ", with: "+")
print(str)

我认为Regex是最灵活和可靠的方式：

var str = "This is my string"
let regex = try! NSRegularExpression(pattern: " ", options: [])
let output = regex.stringByReplacingMatchesInString(
    str,
    options: [],
    range: NSRange(location: 0, length: str.characters.count),
    withTemplate: "+"
)
// output: "This+is+my+string"

迅速扩展：

extension String {

    func stringByReplacing(replaceStrings set: [String], with: String) -> String {
        var stringObject = self
        for string in set {
            stringObject = self.stringByReplacingOccurrencesOfString(string, withString: with)
        }
        return stringObject
    }

}

继续使用它就像 let replacedString = yorString.stringByReplacing(replaceStrings: [" ","?","."], with: "+")

函数的速度是我很难为傲的，但是您可以一次性传递一组数组String以进行多个替换。

这是Swift 3的示例：

var stringToReplace = "This my string"
if let range = stringToReplace.range(of: "my") {
   stringToReplace?.replaceSubrange(range, with: "your")
} 

在Swift 4.2中这很容易。只是replacingOccurrences(of: " ", with: "_")用于替换

var myStr = "This is my string"
let replaced = myStr.replacingOccurrences(of: " ", with: "_")
print(replaced)

Xcode 11•Swift 5.1

StringProtocol的变异方法replacingOccurrences可以实现如下：

extension RangeReplaceableCollection where Self: StringProtocol {
    mutating func replaceOccurrences<Target: StringProtocol, Replacement: StringProtocol>(of target: Target, with replacement: Replacement, options: String.CompareOptions = [], range searchRange: Range<String.Index>? = nil) {
        self = .init(replacingOccurrences(of: target, with: replacement, options: options, range: searchRange))
    }
}

var name = "This is my string"
name.replaceOccurrences(of: " ", with: "+")
print(name) // "This+is+my+string\n"

如果您不想使用Objective-C NSString方法，则可以使用split和join：

var string = "This is my string"
string = join("+", split(string, isSeparator: { $0 == " " }))

split(string, isSeparator: { $0 == " " }) 返回一个字符串数组（["This", "is", "my", "string"]）。

join将这些元素与相连+，得到所需的输出："This+is+my+string"。

我已经实现了这个非常简单的功能：

func convap (text : String) -> String {
    return text.stringByReplacingOccurrencesOfString("'", withString: "''")
}

所以你可以这样写：

let sqlQuery = "INSERT INTO myTable (Field1, Field2) VALUES ('\(convap(value1))','\(convap(value2)')

您可以测试一下：

让newString = test.stringByReplacingOccurrencesOfString（“”，withString：“ +”，选项：无，范围：无）

这是上就地发生替换方法的扩展，该方法String没有不必要的副本，并就地进行了所有操作：

extension String {
    mutating func replaceOccurrences<Target: StringProtocol, Replacement: StringProtocol>(of target: Target, with replacement: Replacement, options: String.CompareOptions = [], locale: Locale? = nil) {
        var range: Range<Index>?
        repeat {
            range = self.range(of: target, options: options, range: range.map { self.index($0.lowerBound, offsetBy: replacement.count)..<self.endIndex }, locale: locale)
            if let range = range {
                self.replaceSubrange(range, with: replacement)
            }
        } while range != nil
    }
}

（方法签名还模仿了内置签名 String.replacingOccurrences()方法）

可以按以下方式使用：

var string = "this is a string"
string.replaceOccurrences(of: " ", with: "_")
print(string) // "this_is_a_string"