IS A SET operator checks whether a variable is a VARRAY or NESTED TABLE collection variable : SET « Collections « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. Collections
3. SET

SQL>
SQL>  DECLARE
  2     TYPE list IS TABLE OF INTEGER;
  3     a LIST := list();
  4   BEGIN
  5     IF a IS A SET THEN
  6       dbms_output.put_line('"a" is a set.');
  7     END IF;
  8   END;
  9   /
"a" is a set.

PL/SQL procedure successfully completed.