有人知道如何在Swift中验证电子邮件地址吗?我找到了这个代码:

- (BOOL) validEmail:(NSString*) emailString {

    if([emailString length]==0){
        return NO;
    }

    NSString *regExPattern = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";

    NSRegularExpression *regEx = [[NSRegularExpression alloc] initWithPattern:regExPattern options:NSRegularExpressionCaseInsensitive error:nil];
    NSUInteger regExMatches = [regEx numberOfMatchesInString:emailString options:0 range:NSMakeRange(0, [emailString length])];

    NSLog(@"%i", regExMatches);
    if (regExMatches == 0) {
        return NO;
    } else {
        return YES;
    }
}

但我无法翻译成斯威夫特。


当前回答

更新答案@Arsonik对Swift 2.2的回答,使用比其他提供的解决方案更少的冗长代码:

extension String {
    func isValidEmail() -> Bool {
        let regex = try? NSRegularExpression(pattern: "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$", options: .CaseInsensitive)
        return regex?.firstMatchInString(self, options: [], range: NSMakeRange(0, self.characters.count)) != nil
    }
}

其他回答

因为现在有这么多奇怪的顶级域名,我不再检查顶级域名的长度…

以下是我使用的方法:

extension String {

    func isEmail() -> Bool {
        let emailRegEx = "^[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\\.[a-zA-Z0-9-.]+$"
        return NSPredicate(format:"SELF MATCHES %@", emailRegEx).evaluateWithObject(self)
    } 
}

这里有很多正确答案,但许多“正则表达式”是不完整的,可能会发生像“name@domain”这样的电子邮件结果是有效的电子邮件,但它不是。这里是完整的解决方案:

extension String {

    var isEmailValid: Bool {
        do {
            let regex = try NSRegularExpression(pattern: "(?:[a-z0-9!#$%\\&'*+/=?\\^_`{|}~-]+(?:\\.[a-z0-9!#$%\\&'*+/=?\\^_`{|}~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\\[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])", options: .CaseInsensitive)
            return regex.firstMatchInString(self, options: NSMatchingOptions(rawValue: 0), range: NSMakeRange(0, self.characters.count)) != nil
        } catch {
            return false
        }
    }
}

如果你正在寻找一个干净简单的解决方案,你应该看看https://github.com/nsagora/validation-components。

它包含一个电子邮件验证谓词,很容易集成在你的代码:

let email = "test@example.com"
let rule = EmailValidationPredicate()
let isValidEmail = rule.evaluate(with: email)

在引擎盖后面,它使用RFC 5322 regex (http://emailregex.com):

let regex = "(?:[\\p{L}0-9!#$%\\&'*+/=?\\^_`{|}~-]+(?:\\.[\\p{L}0-9!#$%\\&'*+/=?\\^_`{|}" +
    "~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\" +
    "x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[\\p{L}0-9](?:[a-" +
    "z0-9-]*[\\p{L}0-9])?\\.)+[\\p{L}0-9](?:[\\p{L}0-9-]*[\\p{L}0-9])?|\\[(?:(?:25[0-5" +
    "]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-" +
    "9][0-9]?|[\\p{L}0-9-]*[\\p{L}0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21" +
    "-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])"

我唯一添加到响应列表的是,对于Linux, NSRegularExpression不存在,它实际上是RegularExpression

    func isEmail() -> Bool {

    let patternNormal = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,6}"

    #if os(Linux)
        let regex = try? RegularExpression(pattern: patternNormal, options: .caseInsensitive)
    #else
        let regex = try? NSRegularExpression(pattern: patternNormal, options: .caseInsensitive)
    #endif

    return regex?.firstMatch(in: self, options: [], range: NSMakeRange(0, self.characters.count)) != nil

在macOS和Ubuntu上都能成功编译。

这是一个最新的游乐场兼容版本,使用标准库,所以你不需要维护一个正则表达式:

import Foundation

func isValid(email: String) -> Bool {
  do {
    let detector = try NSDataDetector(types: NSTextCheckingResult.CheckingType.link.rawValue)
    let range = NSRange(location: 0, length: email.count)
    let matches = detector.matches(in: email, options: .anchored, range: range)
    guard matches.count == 1 else { return false }
    return matches[0].url?.scheme == "mailto"
  } catch {
    return false
  }
}

extension String {
  var isValidEmail: Bool {
    isValid(email: self)
  }
}

let email = "test@mail.com"
isValid(email: email) // prints 'true'
email.isValidEmail // prints 'true'