// creating function //

create or replace function dept_std(dept in varchar)
return number IS
 total number(5):=0;
BEGIN
select total_students into total from dept_list dept_list where dept_name=dept;

return total;
END;
/

// end ////




/* calling fuction */

declare
  c number(5);
  Begin
  c:=dept_std('CSE');
  dbms_output.put_line('Total no. of Students: ' || c);
  end;
  /

  /*end  */