Technically IAS 18 is still applicable because IFRS 15 is only mandatorily effective for accounting periods commencing on or after 1 January, 2018 so IAS 18 may still be being applied up to the end of this calendar year
However … early adoption of IFRS 15 is recommended so there are probably few instances where IAS 18 is still being applied
But, of real importance to you is the fact that IAS18 is no longer on the list of P7 examinable documents (and nor is IAS 11) and is fully superseded by IFRS 15