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。
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
}
}
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@Fattie的“THE REASONABLE SOLUTION”的新版本,在Swift 4.1的一个名为String+Email.swift的新文件中测试:
import Foundation
extension String {
private static let __firstpart = "[A-Z0-9a-z]([A-Z0-9a-z._%+-]{0,30}[A-Z0-9a-z])?"
private static let __serverpart = "([A-Z0-9a-z]([A-Z0-9a-z-]{0,30}[A-Z0-9a-z])?\\.){1,5}"
private static let __emailRegex = __firstpart + "@" + __serverpart + "[A-Za-z]{2,6}"
public var isEmail: Bool {
let predicate = NSPredicate(format: "SELF MATCHES %@", type(of:self).__emailRegex)
return predicate.evaluate(with: self)
}
}
所以它的用法很简单:
let str = "mail@domain.com"
if str.isEmail {
print("\(str) is a valid e-mail address")
} else {
print("\(str) is not a valid e-mail address")
}
我只是不喜欢向String对象添加func,因为作为电子邮件地址是它们固有的(或不是)。根据我的理解,Bool属性比func更适合。
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
}
}