[Moradi]

Hi,
I am doing coding. I use Fortran95.
I have some subroutines which contains optional arguments.
When I call them I can use "if () then" or "select case()" to choose whether assign data to these optional arguments or not. As I know even if I assign an undefined data (undefined array; e.g. an allocatable array which i not allocated) to these subroutines, program will not encounter any problem.
My question is: should I actually use a criterion (using "if" or "select case") when I assign data to these subroutines (for example: when I have an allocatable array I can use "if"; so, when the array is not allocated I will not assign it to the optional argument. But, is it necessary)?

Thanks so much.