blank space in multiple email addresses after ","

Question

I am using RegularExpressionValidator to validate multiple email addresses seprated by a comma ","

My below expression works fine for this requirment:

"((\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)*([,])*)*"

Requirment is this expression should be able to handle space after comma in email addresses.

For example my current expression work file for email1@domain.com,email2@domain.com but what it do not do is email1@domain.com, email2@domain.com

I understand there can be many solutions but in my snario best is to enhance this expression.

Please guide me

I can't answer your question, but I do want to point out that your regex [isn't optimal](http://stackoverflow.com/questions/201323/what-is-the-best-regular-expression-for-validating-email-addresses) — , Nov 22 '11 at 06:38

score 5 · Answer 1 · answered Nov 22 '11 at 06:31

You could use your existing regular expression and instead split the string by each comma and trim trailing/leading whitespace:

var emails = input.Split(',');
foreach (var email in emails.Select(ee => ee.Trim()))
{
    if (!emailValidator.IsMatch(email))
    {
        // announce a bad email
    }
}

score 1 · Accepted Answer · answered Nov 22 '11 at 06:27

1

Here is my suggestion:

((\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)*([, ])*)*

That will accept blanks between the e-mail addresses

answered Nov 22 '11 at 06:27

Fischermaen

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Thanks @Fischermaen, your suggestion worked. But can you please also guide why "((\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*)*([,\s])*)*" not work, I read \s indicate a space ? Please guide. – user576510 Nov 22 '11 at 06:37
2

Inside the square brackets every character is interpreted as a character and `\s` will match a `\` and a `s` and not a whitespace as you intended. – Fischermaen Nov 22 '11 at 06:40

score 1 · Answer 3 · answered Nov 22 '11 at 06:31

Besides what Fischermaen said, another options could be to split emails into separate emails, and then validate each email separately.

   var emails = emailString.split(',');
   for(var i = 0; i < emails.length; i++){
      var email = emails[i].trim().replace(',', '');
      // Now you can validate a single, comma-less, space-less email;
   }

blank space in multiple email addresses after ","

3 Answers3