To match pattern or an empty string, use ^$|pattern Explanation ^ and $ are the beginning and end of the string anchors respectively. | is used to denote alternates, e.g. this|that. References regular-expressions.info/Anchors and Alternation On \b \b in most flavor is a “word boundary” anchor. It is a zero-width match, i.e. an empty string, … Read more
You can use the filter_var() function, which gives you a lot of handy validation and sanitization options. filter_var($email, FILTER_VALIDATE_EMAIL) PHP Manual filter_var() Available in PHP >= 5.2.0 If you don’t want to change your code that relied on your function, just do: function isValidEmail($email){ return filter_var($email, FILTER_VALIDATE_EMAIL) !== false; } Note: For other uses (where … Read more
On Android 2.2+ use this: boolean isEmailValid(CharSequence email) { return android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches(); } for example: EditText emailid = (EditText) loginView.findViewById(R.id.login_email); String getEmailId = emailid.getText().toString(); // Check if email id is valid or not if (!isEmailValid(getEmailId)){ new CustomToast().Show_Toast(getActivity(), loginView, “Your Email Id is Invalid.”); }
There are two methods you can sometimes use to determine if a recipient actually exists: You can connect to the server, and issue a VRFY command. Very few servers support this command, but it is intended for exactly this. If the server responds with a 2.0.0 DSN, the user exists. VRFY user You can issue … Read more
You can theoretically have an address without a “.” in. Since technically things such as: user@com user@localserver user@[IPv6:2001:db8::1] Are all valid emails. So the standard HTML5 validation allows for all valid E-mails, including the uncommon ones. For some easy to read explanations (Instead of reading through the standards): http://en.wikipedia.org/wiki/Email_address#Examples Update from a comment: ICANN banned … Read more
The answer to Using a regular expression to validate an email address explains in great detail that the grammar specified in RFC 5322 is too complicated for primitive regular expressions. I recommend a real parser approach like MKEmailAddress. As quick regular expressions solution see this modification of DHValidation: – (BOOL) validateEmail: (NSString *) candidate { … Read more
If you are using .NET Framework 4.5, the solution is to use EmailAddressAttribute which resides inside System.ComponentModel.DataAnnotations. Your code should look similar to this: [Display(Name = “Email address”)] [Required(ErrorMessage = “The email address is required”)] [EmailAddress(ErrorMessage = “Invalid Email Address”)] public string Email { get; set; }
UPDATES http://so.lucafilosofi.com/jquery-validate-e-mail-address-regex/ using new regex added support for Address tags (+ sign) function isValidEmailAddress(emailAddress) { var pattern = /^([a-z\d!#$%&’*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+(\.[a-z\d!#$%&’*+\-\/=?^_`{|}~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+)*|”((([ \t]*\r\n)?[ \t]+)?([\x01-\x08\x0b\x0c\x0e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|\\[\x01-\x09\x0b\x0c\x0d-\x7f\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))*(([ \t]*\r\n)?[ \t]+)?”)@(([a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|[a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF][a-z\d\-._~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]*[a-z\d\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])\.)+([a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|[a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF][a-z\d\-._~\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]*[a-z\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])\.?$/i; return pattern.test(emailAddress); } if( !isValidEmailAddress( emailaddress ) ) { /* do stuff here */ } NOTE: keep in mind that no 100% regex email check exists!
Good cocoa function: -(BOOL) NSStringIsValidEmail:(NSString *)checkString { BOOL stricterFilter = NO; // Discussion http://blog.logichigh.com/2010/09/02/validating-an-e-mail-address/ NSString *stricterFilterString = @”^[A-Z0-9a-z\\._%+-]+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2,4}$”; NSString *laxString = @”^.+@([A-Za-z0-9-]+\\.)+[A-Za-z]{2}[A-Za-z]*$”; NSString *emailRegex = stricterFilter ? stricterFilterString : laxString; NSPredicate *emailTest = [NSPredicate predicateWithFormat:@”SELF MATCHES %@”, emailRegex]; return [emailTest evaluateWithObject:checkString]; } Discussion on Lax vs. Strict – http://blog.logichigh.com/2010/09/02/validating-an-e-mail-address/ And because categories are just better, … Read more
Java: public static boolean isValidEmail(CharSequence target) { return (!TextUtils.isEmpty(target) && Patterns.EMAIL_ADDRESS.matcher(target).matches()); } Kotlin: fun CharSequence?.isValidEmail() = !isNullOrEmpty() && Patterns.EMAIL_ADDRESS.matcher(this).matches() Edit: It will work On Android 2.2+ onwards !! Edit: Added missing ;