How to determine if NULL is contained in an array in Postgres?

Question

How do I determine if NULL is contained in an array in Postgres? Currently using Postgres 9.3.3.

If I test with the following select it returns contains_null =

Answer 1

One more construction, like @Clodoaldo Neto proposed. Just more compact expression:

CREATE TEMPORARY TABLE null_arrays (
      id serial primary key
    , array_data int[]
);

INSERT INTO null_arrays (array_data)
VALUES
      (ARRAY[1,2, NULL, 4, 5])
    , (ARRAY[1,2, 3, 4, 5])
    , (ARRAY[NULL,2, 3, NULL, 5])
;

SELECT 
    *
FROM 
    null_arrays
WHERE
    TRUE = ANY (SELECT unnest(array_data) IS NULL)
;