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

Swift 5中最简单的方法

extension String {
    var isValidEmail: Bool {
        NSPredicate(format: "SELF MATCHES %@", "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,}").evaluate(with: self)
    }
}

例子

"kenmueller0@gmail.com".isValidEmail

返回……

true

其他回答

或者你可以扩展可选文本UITextField:

使用方法:

if  emailTextField.text.isEmailValid() {
      print("email is valid")
}else{
      print("wrong email address")
}

扩展:

extension Optional where Wrapped == String {
    func isEmailValid() -> Bool{
        guard let email = self else { return false }
        let emailPattern = "[A-Za-z-0-9.-_]+@[A-Za-z0-9]+\\.[A-Za-z]{2,3}"
        do{
            let regex = try NSRegularExpression(pattern: emailPattern, options: .caseInsensitive)
            let foundPatters = regex.numberOfMatches(in: email, options: .anchored, range: NSRange(location: 0, length: email.count))
            if foundPatters > 0 {
                return true
            }
        }catch{
            //error
        }
        return false
    }
}

以下是目前Swiftmailer中一个非常简单的方法。其他大多数答案都是老掉牙的。

根据Swiftmailer文档: https://swiftmailer.symfony.com/docs/messages.html#quick-reference

use Egulias\EmailValidator\EmailValidator;
use Egulias\EmailValidator\Validation\RFCValidation;

$validator = new EmailValidator();
$validator->isValid("example@example.com", new RFCValidation()); //true

在我看来,这是迄今为止最简单、最健壮的方法。只需通过Composer安装egalias \EmailValidator库,它应该已经作为SwiftMailer的依赖项引入了。

创建简单的扩展:

extension NSRegularExpression {

    convenience init(pattern: String) {
        try! self.init(pattern: pattern, options: [])
    }
}

extension String {

    var isValidEmail: Bool {
        return isMatching(expression: NSRegularExpression(pattern: "^[A-Z0-9a-z\\._%+-]+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2,4}$"))
    }

    //MARK: - Private

    private func isMatching(expression: NSRegularExpression) -> Bool {
        return expression.numberOfMatches(in: self, range: NSRange(location: 0, length: characters.count)) > 0
    }
}

例子:

"b@bb.pl".isValidEmail //true
"b@bb".isValidEmail //false

你可以扩展以下扩展到任何你需要的:isValidPhoneNumber, isValidPassword等…

我会使用npredicate:

func isValidEmail(_ email: String) -> Bool {        
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

    let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
    return emailPred.evaluate(with: email)
}

对于Swift 3.0之前的版本:

func isValidEmail(email: String) -> Bool {
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

    let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
    return emailPred.evaluate(with: email)
}

对于Swift 1.2之前的版本:

func isValidEmail(email: String) -> Bool {
    let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,64}"

    if let emailPred = NSPredicate(format:"SELF MATCHES %@", emailRegEx) {
        return emailPred.evaluateWithObject(email)
    }
    return false
}

对于Swift 3:

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