iOS邮箱正则表达式

//判断用户输入是否为邮箱

- (BOOL) validateEmail: (NSString *) candidate {

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

    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];

    return [emailTest evaluateWithObject:candidate];

}