6.1.1 Actual Argument and Dummy Argument Association

Actual arguments must agree in order, number, and data type (or structure, for record arguments) with their corresponding dummy arguments. Actual arguments can be scalar references, array name references, aggregate references, alternate return specifiers, or subprogram names. The dummy arguments specified in subprogram definitions, representing corresponding actual arguments, appear as unsubscripted names.

Although dummy arguments are not actual variables, arrays, records, or subprograms, each dummy argument can be declared as though it were a variable, array, record, or subprogram. The following rules apply to using dummy arguments:

• A dummy argument declared as an array can be associated only with an actual argument that is an array or array element of the same data type. The actual argument must not be placed in parentheses. If a dummy argument is an array, it must be no larger than the array that is the actual argument. You can use adjustable arrays to process arrays of different sizes in a single subprogram.

• A dummy argument declared as a record can be associated only with an actual argument that is an aggregate reference for an entity with a matching structure.

• A dummy argument referenced as a subprogram must be associated with an actual argument that has been declared EXTERNAL or INTRINSIC in the calling routine.

The length of a dummy argument with a data type of character must not be greater than the length of its associated actual argument. If the character dummy argument's length is specified as *(*), it uses the length of the associated actual argument. (This is known as a passed-length character argument.)

The following sections discuss several kinds of arguments:

• Adjustable arrays (Section 6.1.1.1)

• Assumed-size arrays (Section 6.1.1.2)

• Automatic arrays (Section 6.1.1.3)

• Passed-length characters (Section 6.1.1.4)

• Hollerith and character constants (Section 6.1.1.5)

• Alternate returns (Section 6.1.1.6)