How can I get the number of days between 2 dates in Oracle?

when subtracting two dates in Oracle By default its return number of days.

--Passing one date parameter and subtracting from current date

select TRUNC(sysdate) - to_date('1/3/2017', 'dd/MM/yyyy') AS DiffDate

  from dual;

--Passing both date parameter and subtracting lower date from greater date

SELECT to_date('2017-03-06', 'YYYY-MM-DD') -

       to_date('2017-03-01', 'YYYY-MM-DD') AS DiffDate

  from dual;

--To get the number of days different in SQL statement

SELECT TRUNC(sysdate) -

       to_date(to_char(created, 'dd/MM/yyyy'), 'dd/MM/yyyy') As Datediff

  FROM dba_objects

 WHERE object_name = 'TABLE_NAME'

   AND owner = 'TABLE_OWNER'

   AND object_type = 'TABLE';