INTENT Statement

Description

The INTENT statement specifies the treatment dummy arguments.

Syntax
 

     INTENT( intent-spec ) [::] dummy-args
 Where:
 

     

         intent-spec is one of
         

             IN OUT IN OUT
     

     

         dummy-args is a comma-separated list of dummy arguments.
 

Remarks

The INTENT(IN OUT) attribute specifies that the dummy argument is intended for use both to receive data from and to return data to the invoking procedure. This is the default behavior if no INTENT attribute is specified.

The INTENT(IN) attribute specifies that the dummy argument is intended to receive data from the invoking procedure. The dummy argument's value may not be altered during the execution of the subprogram.

The INTENT(OUT) attribute specifies that the dummy argument is intended to return data to the invoking procedure. The subprogram must provide a value for all INTENT(OUT) arguments. An INTENT(OUT) dummy variable cannot be referenced within the subprogram until it has been assigned a value. If a value is not supplied in the subprogram, the value of the actual argument will become undefined upon the subprograms return.

The INTENT statement must not contain a dummy argument that is a procedure or a pointer.

Example
       subroutine ex (a,b,c,d,e,f)
         real :: a,b,c
         intent(in) :: a      ! a cannot be assigned a value
         intent(out) b        ! b must be given a value
         intent(in out) c     ! default behavior
         real,intent(in) :: d ! intent attributes
         real,intent(out) :: e
         real,intent(in out) :: f
       end subroutine ex