Regular Expression Not working in C# Code

Question

I'm using this regular expression

^(?=.{0,150}$)\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*

for validating Email Addresses. when I Enter this Email Address : konstinkö[email protected] . It is working using Regular expression validator(it is showing InValidEmail Address), but when validating in C# code it is not working(taking it as validEmail Address)

return System.Text.RegularExpressions.Regex.IsMatch(
    strEmailAddress,
    @"^(?=.{0,150}$)\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*",
    System.Text.RegularExpressions.RegexOptions.IgnoreCase
);

Reubene · Accepted Answer · 2014-07-03 21:05:17Z

1

If I understand your problem you want the address: konstinkö[email protected] to fail validation because it contains Unicode characters. Your regex uses the \w character class which by default matches any word characters, this includes any Unicode characters defined as letters.

You can force \w to be just [a-zA-Z_0-9] by specifying RegexOptions.ECMAScript you code becomes:

return System.Text.RegularExpressions.Regex.IsMatch(
    strEmailAddress,
    @"^(?=.{0,150}$)\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*",
    System.Text.RegularExpressions.RegexOptions.IgnoreCase | System.Text.RegularExpressions.RegexOptions.RegexOptions.ECMAScript
);

Alternatively you could replace the \w with [a-zA-Z_0-9] which would have the same effect.

answered Jul 3, 2014 at 21:05

Reubene

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1 Comment

user3270152 Over a year ago

Thank you , Its Working !! I have used two regular expressions to solve this issue before.

SMI · Accepted Answer · 2014-02-20 07:15:46Z

0

End you Regex with $ as an example see this. http://www.dotnetperls.com/regex-match

answered Feb 20, 2014 at 7:15

SMI

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Comments

ste · Accepted Answer · 2014-02-20 07:17:12Z

0

Try to use this one:

Regex.IsMatch(strEmailAddress, @"^[\\p{L}0-9!#$%&'*+\/=?^_`{|}~-]+(?:\.[\\p{L}0-9!#$%&'*+\/=?^_`{|}~-]+)*@(?:[\\p{L}0-9](?:[\\p{L}0-9-]*[\\p{L}0-9])?\.)+[\\p{L}0-9](?:[\\p{L}0-9-]*[\\p{L}0-9])?$", RegexOptions.IgnoreCase);

it will admit non ASCII character

edited Feb 20, 2014 at 7:17

answered Feb 20, 2014 at 7:12

ste

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3 Comments

user3270152 Over a year ago

It should not admit Non-Ascii Character, I need a regular expression for not accepting Non-Ascii characters ,Special Characters and SPaces

ste Over a year ago

You have to add this condition: [^\x00-\x7F].

user2864740 Over a year ago

@user3270152 ö is not ASCII. Maybe I misunderstood the problem. In any case, in .NET/C#, \w includes non-ASCII Unicode

Eliran Pe'er · Accepted Answer · 2014-02-20 07:28:31Z

0

I think a better solution would be using the System.Net.Mail.MailAddress class to validate the email address.

Try using the following code:

try {
    MailAddress addr = new System.Net.Mail.MailAddress(email);
    return true;
}
catch {
    return false;
}

UPDATE Regex solution:

bool d = Regex.IsMatch("konstinkö[email protected]", @"^([\p{L}\.\-\d]+)@([\p{L}\-\.\d]+)((\.(\p{L}){2,63})+)$", RegexOptions.IgnoreCase);

Works for me.

edited Feb 20, 2014 at 7:28

answered Feb 20, 2014 at 7:17

Eliran Pe'er

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3 Comments

user3270152 Over a year ago

I tried this one aswell , it is not working... it should not admit Non-Ascii Character

Arnaud Bessems Over a year ago

Using a Try/Catch isn't the best way to make a test. You need to test is something accord to a condition, not try to do something and look if it failed or not.

user3270152 Over a year ago

@Eliran , I tried this , it is not working ... it is returning true

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