! Basic Factorial Function Implementation FORTRAN programming example
!
! Written for inclusion as part of the Texas Tech University 
! Atmospheric Sciences Basic Programming Workshop
!
! Copyright 2013, Timothy Sliwinski
!
! This program is free software: you can redistribute it and/or modify
! it under the terms of the GNU General Public License as published by
! the Free Software Foundation, either version 3 of the License, or
! (at your option) any later version.
!
! This program is distributed in the hope that it will be useful,
! but WITHOUT ANY WARRANTY; without even the implied warranty of
! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
! GNU General Public License for more details.
!
! You should have received a copy of the GNU General Public License
! along with this program.  If not, see <http://www.gnu.org/licenses/>.

PROGRAM Factorial

IMPLICIT NONE

INTEGER::num,result
INTEGER::Fact           ! Must declare function variable

num = 4

result = Fact(num) ! Function calls require "=" operator

PRINT*, result

END PROGRAM Factorial
