Select2 – Set val IF selected option == “Apple”

I have a select2 drop down and would like to know the best way to SET a VALUE if the OPTION selected == ” Apple” for instance.

Here is my Select2

<select id="fruit" title="fruit" name="fruit"
                                      class="form-control select2-single">
                                  <option value="">&nbsp;</option>
                                  <option value="">Apple</option>
                                  <option value="">Lemon</option>
                              </select>

What I’d like to achieve is:

If Option “Apple” is selected, SET Value to THISVARIABLE (I get responses from an AJAX Post and would like to dynamically set the Value