title: Join strings with a delimiter only if strings are not null or empty
body: <p>This feels like it should be simple, so sorry if I'm missing something here, but I'm trying to find a simple way to concatenate only non-null or non-empty strings.</p>
  
  <p>I have several distinct address fields:</p>
  
  <pre><code>var address;
  var city;
  var state;
  var zip;
  </code></pre>
  
  <p>The values for these get set based on some form fields in the page and some other js code.</p>
  
  <p>I want to output the full address in a <code>div</code>, delimited by comma + space, so something like this:</p>
  
  <pre><code>$("#addressDiv").append(address + ", " + city + ", " + state + ", " + zip);
  </code></pre>
  
  <p>Problem is, one or all of these fields could be null/empty.</p>
  
  <p>Is there any simple way to join all of the non-empty fields in this group of fields, without doing a check of the length of each individually before adding it to the string?</p>