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Section Call By Semantics: Call By Reference¶

Adapted from: https://github.com/gjbex/Fortran-MOOC/tree/master/source_code/call_by_semantics

This program demonstrates calling by reference in Fortran.¶

program call_by_reference
    implicit none
    integer :: m
    m = 5
    print *, m
    call increment(m)
    print *, m

contains

    subroutine increment(n)
        implicit none
        integer, intent(inout) :: n

        n = n + 1
    end subroutine increment

end program call_by_reference

The above program is compiled and run using Fortran Package Manager (fpm):

Build the Program using FPM (Fortran Package Manager)¶

import os
root_dir = os.getcwd()

code_dir = root_dir + "/" + "Fortran_Code/Section_Call_By_Semantics_Call_By_Reference"

%%capture
%%writefile section_call_by_semantics_call_by_reference.f90
program call_by_reference
    implicit none
    integer :: m
    m = 5
    print *, m
    call increment(m)
    print *, m

contains

    subroutine increment(n)
        implicit none
        integer, intent(inout) :: n

        n = n + 1
    end subroutine increment

end program call_by_reference

!bat *.f90

───────┬────────────────────────────────────────────────────────────────────────
       │ File: section_call_by_semantics_call_by_reference.f90
───────┼────────────────────────────────────────────────────────────────────────
   1   │ program call_by_reference
   2   │     implicit none
   3   │     integer :: m
   4   │     m = 5
   5   │     print *, m
   6   │     call increment(m)
   7   │     print *, m
   8   │ 
   9   │ contains
  10   │ 
  11   │     subroutine increment(n)
  12   │         implicit none
  13   │         integer, intent(inout) :: n
  14   │ 
  15   │         n = n + 1
  16   │     end subroutine increment
  17   │ 
  18   │ end program call_by_reference
───────┴────────────────────────────────────────────────────────────────────────

os.chdir(code_dir)

build_status = os.system("fpm build 2>/dev/null")

Run the Program using FPM (Fortran Package Manager)¶

exec_status = os.system("fpm run 2>/dev/null")

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