Get selected option in Select2 event, when multiple options can be selected

Question

How can I get hold on the <option> that was just selected when listening to the select2:select event? Note that this is simple when using a single-select, as when only one option is selected, that must be the one that was just selected. I would like to also be able to find the option that was just selected when using a multiple-select (<select multiple>).

In the select2:unselect event, the unselected <option> is available through e.params.data.element, but it is not so in the select2:select event. I do not see a reason why the <option> should not be available, since it is created at this time. For the select2:selecting event, however, the <option> is not yet created, and obviously cannot be available when the event is fired.

Answer 1

I've used the following to get the current selected in Select2 (it's for version 4 and up):

// single value
var test = $('#test');
test.on("select2:select", function(event) {
  var value = $(event.currentTarget).find("option:selected").val();
  console.log(value);
});

UPDATE: Multi Selected Values (with and without last selected)

// multi values, with last selected
var old_values = [];
var test = $("#test");
test.on("select2:select", function(event) {
  var values = [];
  // copy all option values from selected
  $(event.currentTarget).find("option:selected").each(function(i, selected){ 
    values[i] = $(selected).text();
  });
  // doing a diff of old_values gives the new values selected
  var last = $(values).not(old_values).get();
  // update old_values for future use
  old_values = values;
  // output values (all current values selected)
  console.log("selected values: ", values);
  // output last added value
  console.log("last added: ", last);
});