Regular Expressions?

[Arpan]

Using RegularExpression, the following TextBox ensures that users enter
a valid e-mail address which has a '@' & ends with ".com":

<asp:TextBox id="txtEMail" runat="server"/>
<asp:RegularExpressionValidator ControlToValidate="txtEMail"
ValidationExpression="\w+\@\w+\.com" ErrorMessage="Invalid Email ID"
runat="server"/>

I have gone through many articles on RegularExpressions available on
the Net but have never come across the "w" RegularExpression character.
I know what the other RegularExpression characters used above do but
what is this "w"? What does "w" mean here"? Does it signify a word
(which can be just about anything)?

Similarly, consider the following RegularExpression:

href\\s*=\\s*(\"([^\"]*)\"|(\\S+))

The above RegularExpression means 'href' followed by zero or more white
spaces (\s*), then by '=', then by zero or more white spaces again.
This is then followed by a double quote (\"), then by zero or more
occurences of anything that's not a double quote ([^\"]*), followed by
a double quote 'or' one or more non-white space characters (\S+).

Like the characters "w", "s", "S", are there any other letters from 'a'
to 'z' (or from 'A' to 'Z') that have a special meaning in
RegularExpressions? If yes, what are they?

Thanks,

Arpan

 

[Mischa Kroon]

Like the characters "w", "s", "S", are there any other letters from 'a'

to 'z' (or from 'A' to 'Z') that have a special meaning in
RegularExpressions? If yes, what are they?

Answer:

http://www.regexlib.com/CheatSheet.aspx

 

[Arpan]

Thanks for the URL, Mischa.

Regards,

Arpan

Answer:

http://www.regexlib.com/CheatSheet.aspx

 

[Hans Kesting]

Using RegularExpression, the following TextBox ensures that users enter

a valid e-mail address which has a '@' & ends with ".com":

<asp:TextBox id="txtEMail" runat="server"/>
<asp:RegularExpressionValidator ControlToValidate="txtEMail"
ValidationExpression="\w+\@\w+\.com" ErrorMessage="Invalid Email ID"
runat="server"/>

Just some remarks:
- there are e-mail addresses that end in something other than ".com"
(such as two-letter country codes). Do you *really* want to limit to
..com addresses?
- the "\w+\.com" will only accept "company.com", not
"subdomain.company.com". Is that *really* a requirement?

Hans Kesting

 

[Kevin Spencer]

Yes, in fact, the rules regarding valid SMTP email addresses are quite
complex, if you really want to validate an email address. However, it should
also be noted that a valid email address is not necessarily a correct email
address. That is, it may or may not be spelled correctly, and may or may not
point to a valid email account. So, the validation for an email address
varies according to the requirements.

--
HTH,

Kevin Spencer
Microsoft MVP
Professional Chicken Magician

A man, a plan, a canal.
a palindrome that has gone to s**t.

 

[Kevin Spencer]

The Microsoft MSDN library also has an excellent reference:

http://msdn.microsoft.com/library/d...l/cpconRegularExpressionsLanguageElements.asp

--
HTH,

Kevin Spencer
Microsoft MVP
Professional Chicken Magician

A man, a plan, a canal.
a palindrome that has gone to s**t.