aref returns the nth element of an array, string or string_session, where nth is a zero-based index. If the first argument is a string or string_session, the integer ASCII value of the nth character is returned. If the first argument is an array of any, then the corresponding element is returned.
An integer character code or nth element as whatever type the element is if arg is an array or vector (heterogeneous array.)
SQL> select aref ('Abacus', 0); callret VARCHAR _______________________________________________________________________________ 65 1 Rows. -- 3 msec. SQL> select aref (vector ('Primero', 2, 3.333), 2); callret VARCHAR _______________________________________________________________________________ 3.333 1 Rows. -- 4 msec. SQL>