jquery - using .done() successively is giving the same results as .then() / .done()

Question

Edit - please see notes at the bottom on why I don\'t believe this is a duplicate question

Using jquery 3.2.1 and Bootstrap 3.3.7

Part of my application

Answer 1

This question is duplicate. jquery-deferreds-and-promises-then-vs-done

In short:

promise.then( doneCallback, failCallback )
// was equivalent to
promise.done( doneCallback ).fail( failCallback )