ASSOCIATED — Status of a pointer or pointer/target pair#

ASSOCIATED(POINTER, TARGET)#

ASSOCIATED(POINTER [, TARGET]) determines the status of the pointer POINTER or if POINTER is associated with the target TARGET.

Parameters
  • POINTERPOINTER shall have the POINTER attribute and it can be of any type.

  • TARGET – (Optional) TARGET shall be a pointer or a target. It must have the same type, kind type parameter, and array rank as POINTER.

Returns

ASSOCIATED(POINTER) returns a scalar value of type LOGICAL(4). There are several cases:

  • When the optional TARGET is not present then ASSOCIATED(POINTER) is true if POINTER is associated with a target; otherwise, it returns false.

  • If TARGET is present and a scalar target, the result is true if TARGET is not a zero-sized storage sequence and the target associated with POINTER occupies the same storage units. If POINTER is disassociated, the result is false.

  • If TARGET is present and an array target, the result is true if TARGET and POINTER have the same shape, are not zero-sized arrays, are arrays whose elements are not zero-sized storage sequences, and TARGET and POINTER occupy the same storage units in array element order. As in case(B), the result is false, if POINTER is disassociated.

  • If TARGET is present and an scalar pointer, the result is true if TARGET is associated with POINTER, the target associated with TARGET are not zero-sized storage sequences and occupy the same storage units. The result is false, if either TARGET or POINTER is disassociated.

  • If TARGET is present and an array pointer, the result is true if target associated with POINTER and the target associated with TARGET have the same shape, are not zero-sized arrays, are arrays whose elements are not zero-sized storage sequences, and TARGET and POINTER occupy the same storage units in array element order. The result is false, if either TARGET or POINTER is disassociated.

Standard:

Fortran 90 and later

Class:

Inquiry function

Syntax:
RESULT = ASSOCIATED(POINTER [, TARGET])
Example:
program test_associated
   implicit none
   real, target  :: tgt(2) = (/1., 2./)
   real, pointer :: ptr(:)
   ptr => tgt
   if (associated(ptr)     .eqv. .false.) call abort
   if (associated(ptr,tgt) .eqv. .false.) call abort
end program test_associated
See also:

NULL — Function that returns an disassociated pointer