Data Type Oracle PLSQL

SQL>
SQL> DECLARE
  2     lv_three_month_forecast_date DATE         := ADD_MONTHS(SYSDATE,3);
  3     lv_current_user_txt          VARCHAR2(40) := TO_CHAR(UID) ||
  4                                                  ': ' || USER;
  5     lv_date_as_number_num        PLS_INTEGER  := TO_NUMBER(TO_CHAR(
  6                                                  SYSDATE, 'YYYYMMDD'));
  7  BEGIN
  8     DBMS_OUTPUT.PUT_LINE(lv_three_month_forecast_date);
  9     DBMS_OUTPUT.PUT_LINE(lv_current_user_txt);
 10     DBMS_OUTPUT.PUT_LINE(lv_date_as_number_num);
 11  END;
 12  /
19-SEP-08
36: RNTSOFT
20080619
PL/SQL procedure successfully completed.
SQL>