push procedure pop function with sequence number in oracle - oracle

Question

I want to write code for push with procedure and pop with Function .
create or replace package pushpop_demo as
procedure push(val varchar2);
function pop return varchar2;
end pushpop_demo;
create or replace package body pushpop_demo as
subtype my_string_subtype is varchar2(100);
type varchar2_ntt is table of my_string_subtype;
stuff varchar2_ntt := varchar2_ntt();
procedure push(val varchar2)
is
begin
stuff.extend;
stuff(stuff.last) := val;
end push;
function pop return varchar2
is
subtype my_string_subtype varchar2(100);
begin
if stuff is not empty then
val := stuff(stuff.last);
stuff.delete(stuff.last);
end if;
return val;
end pop ;
but I get error , my question is how can I do this problem with sequence number ??? or other solution .my code does not run anyway . also I do not want use the package .just with procedure and Function .please help me

Answer 1

You need / statement terminators to terminate each PL/SQL block.
You are missing an END; statement at the end of the package body.
You have not declared the VAL variable in the function.
You do not want to re-declare the my_string_subtype type (as it will shadow sub-type declared in the package body).
You can initialise the collection in the declaration section or an alternative is to initialise it in the BEGIN ... END section of the package body.
create or replace package pushpop_demo as
procedure push(val varchar2);
function pop return varchar2;
end pushpop_demo;
/
create or replace package body pushpop_demo as
subtype my_string_subtype is varchar2(100);
type varchar2_ntt is table of my_string_subtype;
stuff varchar2_ntt; -- := varchar2_ntt();
procedure push(val varchar2)
is
begin
stuff.extend;
stuff(stuff.last) := val;
end push;
function pop return varchar2
is
val my_string_subtype;
begin
if stuff is not empty then
val := stuff(stuff.last);
stuff.delete(stuff.last);
end if;
return val;
end pop;
BEGIN
stuff := varchar2_ntt();
END;
/
Then you can use:
BEGIN
pushpop_demo.push('World');
pushpop_demo.push('Hello');
END;
/
and then:
BEGIN
DBMS_OUTPUT.PUT_LINE(pushpop_demo.pop());
DBMS_OUTPUT.PUT_LINE(pushpop_demo.pop());
END;
/
Outputs:
Hello
World
fiddle