DECLARE
    count number(2) := 10;
BEGIN
    FOR count in 10..20                         (FOR count in REVERSE 10..20)
    LOOP
        dbms_output.put_line("COUNT : " || count);
    END LOOP;
END;

-- FOR count in 10..20 
-- it will print value from 10 to 20
-- FOR count in REVERSE 10..20 
-- it will print value from 20 to 10