title: How do I combine cell values with delimiters from an uncertain number of cells?
body: <p>I have a spreadsheet (exported from a database, so I'm stuck with the output format I'm given) with fourteen columns to indicate which of fourteen decks have been checked. (And yes, the numbers aren't stored as numbers.)
  <a href="https://i.stack.imgur.com/SU5z1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SU5z1.png" alt="Spreadsheet columns with deck numbers"></a></p>
  
  <p>I'd like to combine them all into a single cell with the deck numbers separated by commas. Normally I'd just use a series of <code>&amp;", "&amp;</code> elements, but of course that won't work when it's an uncertain number of decks. I could also use a series of <code>IF</code> functions, but that's going to be pretty cumbersome.</p>
  
  <p>As an example, I'd like the top row in the image to be summarised as "1, 2, 3, 4, 5, 6" rather than "1, 2, 3, 4, 5, 6, , , , , , , , "...</p>
  
  <p>Is there a simpler, easier and/or better way of doing it?</p>