title: JSON.stringify() vs array.join(',')
body: <p>In <code>Angular 6</code>, I was using <code>myString.join(',')</code> to join an array of IDs into one long string of comma separated IDs. </p>
  
  <p>When I would send this to the <code>.NET Web API</code>, I noticed only one value, the first ID, was being sent. I then fixed this on the front end by changing <code>myString.join(',')</code> to <code>JSON.stringify(myString.join(','))</code>. Now, on the API, all of the ID's are sent successfully.</p>
  
  <p>I was wondering why this is. I understand that data needs to be sent via <code>JSON</code>, but what is the difference between a <code>JSON</code> string and a front end Typescript string built by <code>.join(',')</code>? I kind of expected just a regular <code>.join()</code> to work, since it is a string.</p>