SQL> declare
  2    v1 integer;
  3    type tarray is table of integer index by binary_integer;
  4    myarray tarray;
  5  begin
  6    v1 := myarray(1);
  7  end;
  8  /
declare
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 6

declare
  v_l_fixed_var_ind varchar2(1);
  i_first_time varchar2(1) := 'Y';

  function subroutine ( p_index in varchar2 ) return varchar2 is
    type t_fixed_var is table of varchar2(1) index by varchar2(3);
    fixed_variable t_fixed_var;
  begin
    if i_first_time = 'Y' then
      fixed_variable('001') := 'F';
      fixed_variable('002') := 'V';
      fixed_variable('003') := 'V';
    end if;
    i_first_time := 'N';

    return fixed_variable( p_index );
  end;
begin
  v_l_fixed_var_ind := subroutine( '003' );
  -- you cannot do this; FIXED_VARIABLE is not available (and hence not containing anything) here
  --v_l_fixed_var_ind := fixed_variable( '001' );
  -- in the next call, FIXED_VARIABLE will be initialized again
  -- of course, it does not contain anything from any previous call
  --v_l_fixed_var_ind := subroutine( '002' );
end;
/

08:20:48 SQL> declare
08:20:58   2     procedure p1 is
08:21:02   3        v1 integer;
08:21:07   4     begin
08:21:11   5        null;
08:21:13   6     end;
08:21:15   7  begin
08:21:16   8     v1 := 1;
08:21:18   9  end;
08:21:18  10  /
   v1 := 1;
   *
ERROR at line 8:
ORA-06550: line 8, column 4:
PLS-00363: expression 'V1' cannot be used as an assignment target
ORA-06550: line 8, column 4:
PL/SQL: Statement ignored


Elapsed: 00:00:01.45
08:21:21 SQL>

SQL> declare
  2    v_l_fixed_var_ind varchar2(1);
  3    i_first_time varchar2(1) := 'Y';
  4
  5    function subroutine ( p_index in varchar2 ) return varchar2 is
  6      type t_fixed_var is table of varchar2(1) index by varchar2(3);
  7      fixed_variable t_fixed_var;
  8    begin
  9      if i_first_time = 'Y' then
 10        fixed_variable('001') := 'F';
 11        fixed_variable('002') := 'V';
 12        fixed_variable('003') := 'V';
 13      end if;
 14      i_first_time := 'N';
 15
 16      return fixed_variable( p_index );
 17    end;
 18  begin
 19    v_l_fixed_var_ind := subroutine( '003' );
 20    -- you cannot do this; FIXED_VARIABLE is not available (and hence not con
taining anything) here
 21    --v_l_fixed_var_ind := fixed_variable( '001' );
 22    -- in the next call, FUIXED_VARIABLE will be initialized again
 23    -- of course, it does not contain anything from any previous call
 24    v_l_fixed_var_ind := subroutine( '002' );
 25  end;
 26  /
declare
*
ERROR at line 1:
ORA-01403: no data found
ORA-06512: at line 16
ORA-06512: at line 24