title: C# - IEnumerable to delimited string
body: <p>What is the functional programming approach to convert an <code>IEnumerable&lt;string&gt;</code> to a delimited string?  I know I can use a loop, but I'm trying to wrap my head around functional programming.  </p>
  
  <p>Here's my example:            </p>
  
  <pre><code>var selectedValues =
  from ListItem item in checkboxList.Items
  where item.Selected
  select item.Value;
  
  var delimitedString = ??
  </code></pre>
  
  <p>.. or could I do this in just the first var assignment (append each result to the previous)?</p>