Character Constant and Hollerith Arguments

If an actual argument is a character constant (for example, 'ABCD'), the corresponding dummy argument must be of type character. If an actual argument is a Hollerith constant (for example, 4HABCD), the corresponding dummy argument must have a numeric data type.

The following example shows character and Hollerith constants being used as actual arguments:

  SUBROUTINE S(CHARSUB, HOLLSUB, A, B)
  EXTERNAL CHARSUB, HOLLSUB
  ...
  CALL CHARSUB(A, 'STRING')
  CALL HOLLSUB(B, 6HSTRING)

The subroutines CHARSUB and HOLLSUB are themselves dummy arguments of the subroutine S. Therefore, the actual argument 'STRING' in the call to CHARSUB must correspond to a character dummy argument, and the actual argument 6HSTRING in the call to HOLLSUB must correspond to a numeric dummy argument.