Question

我必须检测字符串是否包含任何特殊字符。我怎么检查呢？ Swift是否支持正则表达式？

var characterSet:NSCharacterSet = NSCharacterSet(charactersInString: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789")
if (searchTerm!.rangeOfCharacterFromSet(characterSet).location == NSNotFound){
    println("Could not handle special characters")
}

我尝试了上面的代码，但只有当我将第一个字符作为特殊字符输入时才匹配。

Answer 1

您的代码检查字符串中的字符是否来自给定集合。你想要的是检查给定集合中

if (searchTerm!.rangeOfCharacterFromSet(characterSet.invertedSet).location != NSNotFound){
    println("Could not handle special characters")
}

您也可以使用正则表达式实现此目的：

let regex = NSRegularExpression(pattern: ".*[^A-Za-z0-9].*", options: nil, error: nil)!
if regex.firstMatchInString(searchTerm!, options: nil, range: NSMakeRange(0, searchTerm!.length)) != nil {
    println("could not handle special characters")

}

模式[^A-Za-z0-9]匹配范围A-Z中不的字符， a-z或0-9。

Swift 2的更新：

let searchTerm = "a+b"

let characterset = NSCharacterSet(charactersInString: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
if searchTerm.rangeOfCharacterFromSet(characterset.invertedSet) != nil {
    print("string contains special characters")
}

Swift 3的更新：

let characterset = CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")
if searchTerm.rangeOfCharacter(from: characterset.inverted) != nil {
    print("string contains special characters")
}

Answer 2

这个答案可以帮助那些使用 Swift 4.1

的人

func hasSpecialCharacters() -> Bool {

    do {
        let regex = try NSRegularExpression(pattern: ".*[^A-Za-z0-9].*", options: .caseInsensitive)
        if let _ = regex.firstMatch(in: self, options: NSRegularExpression.MatchingOptions.reportCompletion, range: NSMakeRange(0, self.count)) {
            return true
        }

    } catch {
        debugPrint(error.localizedDescription)
        return false
    }

    return false
}

从@Martin R的回答中引用。

Answer 3

反转你的字符集会起作用，因为在你的字符集中你有所有有效的字符：

var characterSet:NSCharacterSet = NSCharacterSet(charactersInString: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789")
if (searchTerm!.rangeOfCharacterFromSet(characterSet.invertedSet).location == NSNotFound){
    println("No special characters")
}

希望这会有所帮助.. :)

Answer 4

@Martin R答案很棒，我只想更新它（第二部分）到Swift 2.1版本

let regex = try! NSRegularExpression(pattern: ".*[^A-Za-z0-9].*", options: NSRegularExpressionOptions())
if regex.firstMatchInString(searchTerm!, options: NSMatchingOptions(), range:NSMakeRange(0, searchTerm!.characters.count)) != nil {
    print("could not handle special characters")
}

我使用try!，因为我们可以确定它会创建一个正则表达式，它不会基于任何动态类型的数据

Answer 5

密码验证以下内容： - （密码长度至少为八个字符，一个特殊字符，一个大写字母，一个小写字母和一个数字）

var isValidateSecialPassword : Bool {

        if(self.count>=8 && self.count<=20){
        }else{
            return false
        }
        let nonUpperCase = CharacterSet(charactersIn: "ABCDEFGHIJKLMNOPQRSTUVWXYZ").inverted
        let letters = self.components(separatedBy: nonUpperCase)
        let strUpper: String = letters.joined()

        let smallLetterRegEx  = ".*[a-z]+.*"
        let samlltest = NSPredicate(format:"SELF MATCHES %@", smallLetterRegEx)
        let smallresult = samlltest.evaluate(with: self)

        let numberRegEx  = ".*[0-9]+.*"
        let numbertest = NSPredicate(format:"SELF MATCHES %@", numberRegEx)
        let numberresult = numbertest.evaluate(with: self)

        let regex = try! NSRegularExpression(pattern: ".*[^A-Za-z0-9].*", options: NSRegularExpression.Options())
        var isSpecial :Bool = false
        if regex.firstMatch(in: self, options: NSRegularExpression.MatchingOptions(), range:NSMakeRange(0, self.count)) != nil {
            print("could not handle special characters")
            isSpecial = true
        }else{
            isSpecial = false
        }
        return (strUpper.count >= 1) && smallresult && numberresult && isSpecial
    }

Answer 6

根据特殊字符的定义，您可以使用：

let chars =  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLKMNOPQRSTUVWXYZ0123456789"

chars.canBeConvertedToEncoding(NSASCIIStringEncoding)

Answer 7

使用 Swift 5 ，您可以做到

if let hasSpecialCharacters =  "your string".range(of: ".*[^A-Za-z0-9].*", options: .regularExpression) != nil {}

Answer 8

两种解决方案：

1）

extension String {
    var stripped: String {
        let okayChars = Set("abcdefghijklmnopqrstuvwxyz ABCDEFGHIJKLKMNOPQRSTUVWXYZ")
        return self.filter {okayChars.contains($0) }
    }
}

2）

class TrimDictionary {

    static func trimmedWord(wordString: String) -> String {
        var selectedString = wordString

        let strFirst = selectedString.first
        let strLast = selectedString.last

        let characterset = CharacterSet(charactersIn: "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
        if strFirst?.description.rangeOfCharacter(from: characterset.inverted) != nil {
            selectedString = String(selectedString.dropFirst())
        }
        if strLast?.description.rangeOfCharacter(from: characterset.inverted) != nil {
            selectedString = String(selectedString.dropLast())
        }
        return selectedString
    }
}

Answer 9

可以通过在正则表达式子句中使用inversion（^）来简化Mahendra的答案。此外，使用caseInsensitive选项时，您不需要A-Z和a-z，因为Swift可以为您解决这种情况：

extension String {

  func containsSpecialCharacters(string: String) -> Bool {
        
        do {
            let regex = try NSRegularExpression(pattern: "[^a-z0-9 ]", options: .caseInsensitive)
            if let _ = regex.firstMatch(in: string, options: [], range: NSMakeRange(0, string.count)) {
                return true
            } else {
                return false
            }
        } catch {
            debugPrint(error.localizedDescription)
            return true
        }
    }

Answer 10

出于文件名清理的目的，我更喜欢检测无效字符，而不是提供允许的字符集。毕竟，许多非英语用户需要带重音符号。以下功能受this gist的启发：

func checkForIllegalCharacters(string: String) -> Bool {
    let invalidCharacters = CharacterSet(charactersIn: "\\/:*?\"<>|")
    .union(.newlines)
    .union(.illegalCharacters)
    .union(.controlCharacters)

    if string.rangeOfCharacter(from: invalidCharacters) != nil {
        print ("Illegal characters detected in file name")
        // Raise an alert here
        return true
    } else {
    return false
}

检查字符串是否包含Swift中的特殊字符

10 个答案: