Regular Expression

[swetham]

I have a written a code to validate email id as,

Function EmailAddressCheck(ByVal emailAddress As String) As Boolean

Dim pattern As String = "^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"

Dim emailAddressMatch As System.Text.RegularExpressions.Match = System.Text.RegularExpressions.Regex.Match(emailAddress, pattern)
If emailAddressMatch.Success Then
EmailAddressCheck = True
Else
EmailAddressCheck = False
End If

End Function


I need to validate like after '.' only 3 characters should be present.

Can anyone help me?

 

[jges]

If you want only 3 characters, use {3} after that part of the pattern.

 

[swetham]

Can you please tell me where to place the {3} and i also need the condition that before @ there can be 1 character also.

 

[swetham]

sorry, the required condition is the number of characters after .(dot) should not be greater than 3 and the number of characters before @ should be minimun 1

 

[jges]

Perhaps this website (and this webpage in particular) will be of use:

http://www.regular-expressions.info/email.html

 

[SgtJarrow]

While not the answer to your issue, I wanted to pose the question:

Are you sure you really want this check??

I am not a regular expression expert, but it seems to me if you are validating on only three characters in the last part of the domain name, you will run into issues.

Examples:
xxxxxxxx@tampabay.rr.com (my primary email domain name)
xxxx@somewhere.fm (media domain names - like radio stations)
xxxx@somewhere.info (email attached to an informational site)
xxxx@somewhere.xx (the xx domain at the end here can be replaced by emails from various countries - .ru, .nz)

I only pose this question because you may not be aware of the fact that a domain name no longer HAS to end with a three character extension. Just like the

http://www part

of an http website address is not always true anymore. As the internet continues to grow (and especially the use of IPv6), the concepts of .com, .org, .biz, etc are quickly expanding.

If you limit your input to only a three part .com-like extension, you may be creating problems for people who do not have this "semi-standard" convention in their email address.

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Robert L. Johnson III
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VB.NET Programmer