How to insert into collection type of objects?

Question

Hello,
Can any one help with the follwoing code below,where i cant insert into an instance of the table type within the pl/sql block.
create type courselist is table of varchar2(25);
create type student as object
(name varchar2(20),
courses courselist);
create type student_typ is table of student;
create or replace procedure test_nested as
my_courses1 student_typ:=student_typ(student('harry',courselist('eco 2010','math 2010','acct 2010')));
n_numb number;
begin
dbms_output.put_line('hello initial'||'-'||my_courses1.count);
my_courses1.extend;
n_numb:=my_courses1.next(my_courses1.first);
dbms_output.put_line('Next Subscript :'||n_numb);
dbms_output.put_line('hello after extend'||'-'||my_courses1.count);
my_courses1(n_numb):=student_typ(student('Potter',courselist('eng 2010','bio 2010')));
dbms_output.put_line(my_courses1(n_numb).name);
exception
when others then
dbms_output.put_line(sqlerrm);
end;

Answer 1

Look at:
my_courses1(n_numb):=student_typ(student('Potter',courselist('eng 2010','bio 2010')));my_courses1(n_numb) is of student type while student_typ(student('Potter',courselist('eng 2010','bio 2010'))) is table of student type. Change it to:
my_courses1(n_numb):=student('Potter',courselist('eng 2010','bio 2010'));and you will be fine:
SQL> create or replace
  2    procedure test_nested
  3      as
  4          my_courses1 student_typ:=student_typ(student('harry',courselist('eco 2010','math 2010','acct 2010')));
  5          n_numb number;
  6      begin
  7          dbms_output.put_line('hello initial'||'-'||my_courses1.count);
  8          my_courses1.extend;
  9          n_numb:=my_courses1.next(my_courses1.first);
10          dbms_output.put_line('Next Subscript :'||n_numb);
11          dbms_output.put_line('hello after extend'||'-'||my_courses1.count);
12          my_courses1(n_numb):=student('Potter',courselist('eng 2010','bio 2010'));
13          dbms_output.put_line(my_courses1(n_numb).name);
14        exception
15          when others then
16            dbms_output.put_line(sqlerrm);
17  end;
18  /
Procedure created.
SQL> exec test_nested
hello initial-1
Next Subscript :2
hello after extend-2
Potter
PL/SQL procedure successfully completed.
SQL> SY.