string.Split C# keeps text outside delimiters

Question

I am trying to take a list of eMail addresses along with first and last names and convert them to a CSV format. My eMail addresses are in the following format:

First, Last <email1@example.com>; First, Last <email2@example.com>;

The output I need is the following:

email1@example.com,email2@example.com

I am using the following code:

string[] addresses = addresses_Delimited.Split(new Char[] { '<', '>' });

addresses_Delimited is my list of addresses in the original format.

The problem is that it is not eliminating first and last names; instead it is returning first and last names as entries in the array addresses. So, addresses[0] = "First, Last", addresses[1] = "email1@example.com", and addresses[2] = "; First, Last". All first and last name entries after the first one have a semicolon in them.

How do I make string.Split remove all text outside "<" and ">"? Do I need to use something else?

@L-Three Are you saying I can't do this with `string.Split`? — ServerS, May 05 '15 at 14:30
Check this Link. http://stackoverflow.com/questions/2333835/extract-all-email-address-from-a-text-using-c-sharp — Prashant, May 05 '15 at 14:30

score 6 · Accepted Answer · answered May 05 '15 at 14:29

Rather than using a Split which does not care that the delimiters are paired up, use a regular expression like this:

<([^>]+)>

When you apply this regex to your input strings, you would capture the content of angular brackets into capturing group number 1:

var s = "First, Last <email1@example.com>; First, Last <email2@example.com>;";
Regex regex = new Regex(@"<([^>]+)>");
foreach (Match m in regex.Matches(s)) {
    Console.WriteLine(m.Groups[1]);
}

Demo.

score 2 · Answer 2 · answered May 05 '15 at 14:32

Split won't work in this case. You need to use Regular Expressions. Try this

// using System.Text.RegularExpressions;
// pattern = any number of arbitrary characters between < and >.
var pattern = @"\<(.*?)\>";
var matches = Regex.Matches(addresses_Delimited, pattern);

foreach (Match m in matches) {
    Console.WriteLine(m.Groups[1]);
}

Carl Prothman · Answer 3 · 2015-05-05T15:30:34.560

0

Split by ";' first, then by "<" and ">".

string inputEmails = "First1, Last1 <email1@example.com>; First2, Last2 <email2@example.com>;";
string[] inputEmailsArray = inputEmails.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
foreach (string email in inputEmailsArray)
{
    string[] inputEmailArray = email.Split(new char[] { '<', '>' }, StringSplitOptions.RemoveEmptyEntries);
    foreach (string emailPart in inputEmailArray)
    {
        string s = emailPart;   // First1, Last1     // email1@example.com
    }
}

edited May 05 '15 at 15:30

answered May 05 '15 at 14:38

Carl Prothman

1,461
13
23

This assume your input file is in correct format. Otherwise use the Regular Expression (see other answers) – Carl Prothman May 05 '15 at 14:40

score 0 · Answer 4 · answered May 05 '15 at 14:42

You can do it with split - but it's really ugly:

var text = "First, Last <email1@example.com>; First, Last <email2@example.com>;";

var t = text.TrimEnd(';').Split(';');
foreach (var m in t)
{
    Console.WriteLine(m.Split('<')[1].TrimEnd('>'));
}

Use RegularExpression instead.

allonhadaya · Answer 5 · 2015-05-05T15:24:29.760

Assuming (and this is a big assumption) that there are no ; characters in any names or emails and that there are no , characters in any emails, this will work:

using System.Linq;
using System.Net.Mail;

...

var input = "First, Last <email1@example.com>; First, Last <email2@example.com>;";

var emails = String.Join(",", input
  .Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries)
  .Select(s => new MailAddress(s).Address));

string.Split C# keeps text outside delimiters

5 Answers5