CREATE OR REPLACE PACKAGE pk_demo
AS
   PROCEDURE p_proc_1;

   FUNCTION f_func_1
      RETURN NUMBER;
END pk_demo;
/

CREATE OR REPLACE PACKAGE BODY pk_demo
IS
   a   NUMBER;

   FUNCTION f_func_1
      RETURN NUMBER
   AS
   BEGIN
      RETURN 10;
   END f_func_1;

   PROCEDURE p_proc_1
   IS
      li_num   NUMBER;
   BEGIN
      SELECT f_func_1
        INTO li_num
        FROM DUAL;

      DBMS_OUTPUT.put_line (li_num);
   END p_proc_1;
//one-time-only procedure defination
BEGIN
   DBMS_OUTPUT.put_line ('u r in the only block execution');
END pk_demo;
/

SQL>  execute pk_demo.p_proc_1;
you are in the only block execution
10

PL/SQL procedure successfully completed.

//here in the following the output is not same as earlier
SQL> execute pk_demo.p_proc_1;
10

PL/SQL procedure successfully completed.