Live ORACLE

DECLARE
  TYPE t1 IS VARRAY (10) OF INTEGER;

  TYPE nt1 IS VARRAY (10) OF t1;                   -- multilevel varray type

  va    t1      := t1 (2, 3, 5);
-- initialize multilevel varray
  nva   nt1     := nt1 (va, t1 (55, 6, 73), t1 (2, 4), va);
  i     INTEGER;
  va1   t1;
BEGIN
-- multilevel access
  i := nva (2) (3);                                   -- i will get value 73
  DBMS_OUTPUT.put_line ('I = ' || i);
-- add a new varray element to nva
  nva.EXTEND;
-- replace inner varray elements
  nva (5) := t1 (56, 32);
  nva (4) := t1 (45, 43, 67, 43345);
-- replace an inner integer element
  nva (4) (4) := 1;                                 -- replaces 43345 with 1
-- add a new element to the 4th varray element
-- and store integer 89 into it.
  nva (4).EXTEND;
  nva (4) (5) := 89;
END;
/

Multilevel VARRAY