I'm pretty new in the Fortran world. I get a piece of code, where I find difficulty in understanding it.
Let's say in module A, var is declared as a parameter of integer type:
integer, parameter :: var = 81
Then in another module B, an array with the name var is declared:
integer :: var(2)
When these modules are used in a third module C:
use A
use B
Won't there be conflict in the names? Or the two members of the array var will take the value 81?
There will be a compile time error when you attempt to access the variable var in your described case. The specific error will look like:
Error: Name 'var' at (1) is an ambiguous reference to 'var' from module 'a'
Are those variables meant to be globally scoped? You can declare one (or both) of them with private so they are scoped to the module and do not pollute the global scope. In this case though, module C would not be able to use the private variable. Another option is to limit what is imported in your use statement with:
use A, only: some_variable1, some_other_variable
use B, only: var
This would let var from B into the scope of C, and would hide var from A.
If you have to have both variables in module C, you can rename one when you use the module. E.g.:
use A, varA => var
use B, varB => var
which lets you access the variables var in each module by the names varA and varB.
See this example:
module A
integer, parameter :: var = 81
contains
end module
module B
integer :: var(2)
contains
end module
module C
use A, varA => var
use B, varB => var
contains
end module
program test
use C
print *, varA
end program
which will print 81.
var can be renamed on the use statement.
A::var or A->var or A.var whatever the right syntax would be. having to rename things all the time does not seem like a good way to go about these things. This problem have been solved long time ago by Ada for example with its package system.