Fortran Wiki
present

Description

Determines whether an optional dummy argument is present.

Standard

Fortran 95 and later

Class

Inquiry function

Syntax

result = present(a)

Arguments

• a - May be of any type and may be a pointer, scalar or array value, or a dummy procedure. It shall be the name of an optional dummy argument accessible within the current subroutine or function.

Return value

Returns either true if the optional argument a is present, or false otherwise.

Example

program test_present
  write(*,*) f(), f(42)      ! "f t"
contains
  logical function f(x)
    integer, intent(in), optional :: x
    f = present(x)
  end function
end program