Oracle PL/SQL Tutorial/Collections/IS NULL

IS NULL operator checks whether a variable value is null

   <source lang="sql">

SQL> SQL> DECLARE

 2     var BOOLEAN;
 3    BEGIN
 4     IF var IS NULL THEN
 5      dbms_output.put_line("It is null.");
 6     END IF;
 7    END;
 8    /

It is null. PL/SQL procedure successfully completed. SQL> SQL> SQL></source>