Private function in Fortran

Question

How do I declare a private function in Fortran?

Answer 1

This will only work with a Fortran 90 module. In your module declaration, you can specify the access limits for a list of variables and routines using the "public" and "private" keywords. I usually find it helpful to use the private keyword by itself initially, which specifies that everything within the module is private unless explicitly marked public.

In the code sample below, subroutine_1() and function_1() are accessible from outside the module via the requisite "use" statement, but any other variable/subroutine/function will be private.

module so_example
  implicit none

  private

  public :: subroutine_1
  public :: function_1

contains

  ! Implementation of subroutines and functions goes here  

end module so_example