我需要知道一个字符串是否包含整数,以确保用户输入的名字是有效的全名, 为此,我需要让用户只输入字符,或者验证用户输入的字符串中没有整数。 感谢所有的帮助。
您可以使用 Foundation 方法处理 Swift 字符串,在此处应该这样做。 NSString
内置了使用 NSCharacterSet
检查某些类型的字符是否存在的方法。这可以很好地转换为 Swift:
var str = "Hello, playground1"
let decimalCharacters = CharacterSet.decimalDigits
let decimalRange = str.rangeOfCharacter(from: decimalCharacters)
if decimalRange != nil {
print("Numbers found")
}
如果您有兴趣限制可键入的内容,您应该实现 UITextFieldDelegate
和方法 textField(_:shouldChangeCharactersIn:replacementString:)
,以防止人们首先输入这些字符。
使用字符串类的rangeOfCharacter
方法,简单的Swift 4版本:
let numbersRange = stringValue.rangeOfCharacter(from: .decimalDigits)
let hasNumbers = (numbersRange != nil)
这是我现在用来检查字符串是否包含数字的方法
func doStringContainsNumber( _string : String) -> Bool{
let numberRegEx = ".*[0-9]+.*"
let testCase = NSPredicate(format:"SELF MATCHES %@", numberRegEx)
let containsNumber = testCase.evaluateWithObject(_string)
return containsNumber
}
如果您的字符串包含数字,它将返回true,否则返回false。希望能对您有所帮助。
//A function that checks if a string has any numbers
func stringHasNumber(_ string:String) -> Bool {
for character in string{
if character.isNumber{
return true
}
}
return false
}
/// Check stringHasNumber function
stringHasNumber("mhhhldiddld")
stringHasNumber("kjkdjd99900")
//Swift 3.0 to check if String contains numbers (decimal digits):
let someString = "string 1"
let numberCharacters = NSCharacterSet.decimalDigits
if someString.rangeOfCharacter(from: numberCharacters) != nil
{ print("String contains numbers")}
else if someString.rangeOfCharacter(from: numberCharacters) == nil
{ print("String doesn't contains numbers")}
if (ContainsNumbers(str).count > 0)
{
// Your string contains at least one number 0-9
}
func ContainsNumbers(s: String) -> [Character]
{
return s.characters.filter { ("0"..."9").contains($0)}
}
Swift 2.3 版本可用。
extension String
{
func containsNumbers() -> Bool
{
let numberRegEx = ".*[0-9]+.*"
let testCase = NSPredicate(format:"SELF MATCHES %@", numberRegEx)
return testCase.evaluateWithObject(self)
}
}
使用方法:
//guard let firstname = textField.text else { return }
let testStr1 = "lalalala"
let testStr2 = "1lalalala"
let testStr3 = "lal2lsd2l"
print("Test 1 = \(testStr1.containsNumbers())\nTest 2 = \(testStr2.containsNumbers())\nTest 3 = \(testStr3.containsNumbers())\n")
你需要通过封装它的nsRegularExpression来欺骗Swift使用正则表达式
class Regex {
let internalExpression: NSRegularExpression
let pattern: String
init(_ pattern: String) {
self.pattern = pattern
var error: NSError?
self.internalExpression = NSRegularExpression(pattern: pattern, options: .CaseInsensitive, error: &error)
}
func test(input: String) -> Bool {
let matches = self.internalExpression.matchesInString(input, options: nil, range:NSMakeRange(0, countElements(input)))
return matches.count > 0
}
}
if Regex("\\d/").test("John 2 Smith") {
println("has a number in the name")
}
let numericCharSet = CharacterSet.init(charactersIn: "1234567890")
let newCharSet = CharacterSet.init(charactersIn: "~`@#$%^&*(){}[]<>?")
let sentence = "Tes#ting4 @Charact2er1Seqt"
if sentence.rangeOfCharacter(from: numericCharSet) != nil {
print("Yes It,Have a Numeric")
let removedSpl = sentence.components(separatedBy: newCharSet).joined()
print(sentence.components(separatedBy: newCharSet).joined())
print(removedSpl.components(separatedBy: numericCharSet).joined())
}
else {
print("No")
}
NSString
,然后你可以使用string.containsString(otherString)
,并检查它是否包含一个数字。 - Kendel