Create a print_bool function to display the values of BOOLEAN.

CREATE FUNCTION print_bool (v IN BOOLEAN) 
  RETURN VARCHAR2 
IS 
  v_rtn VARCHAR2(10); 
BEGIN 
  CASE v 
  WHEN TRUE THEN 
    v_rtn := 'TRUE'; 
  WHEN FALSE THEN 
    v_rtn := 'FALSE'; 
  ELSE 
    v_rtn := 'NULL'; 
  END CASE; 
  RETURN v_rtn; 
END print_bool;

DECLARE 
TYPE t_aa 
IS 
  TABLE OF BOOLEAN INDEX BY pls_integer; 
  v_aa1 t_aa := t_aa(1=>FALSE, 
                     2=>TRUE, 
                     3=>NULL); 
BEGIN 
  DBMS_OUTPUT.PUT_LINE(print_bool(v_aa1(1))); 
  DBMS_OUTPUT.PUT_LINE(print_bool(v_aa1(2))); 
  DBMS_OUTPUT.PUT_LINE(print_bool(v_aa1(3))); 
END;

Create package pkg.

CREATE PACKAGE pkg IS 
TYPE rec_t IS 
  RECORD 
  ( year PLS_INTEGER := 2, 
    name VARCHAR2(100) ); 
END;

DECLARE 
  v_rec1 pkg.rec_t := pkg.rec_t(1847,'ONE EIGHT FOUR SEVEN'); 
  v_rec2 pkg.rec_t := pkg.rec_t(year => 1, name => 'ONE'); 
  v_rec3 pkg.rec_t := pkg.rec_t(NULL,NULL); 
 
PROCEDURE print_rec ( pi_rec pkg.rec_t := pkg.rec_t(1847+1,  'a'||'b')) 
IS 
  v_rec1 pkg.rec_t := pkg.rec_t(2847,'TWO EIGHT FOUR SEVEN'); 
BEGIN 
  DBMS_OUTPUT.PUT_LINE(NVL(v_rec1.year,0) ||' ' ||NVL(v_rec1.name,'N/A')); 
  DBMS_OUTPUT.PUT_LINE(NVL(pi_rec.year,0) ||' ' ||NVL(pi_rec.name,'N/A')); 
END; 
BEGIN 
  print_rec(v_rec1); 
  print_rec(v_rec2); 
  print_rec(v_rec3); 
  print_rec(); 
END;