REPORT Z14_16.

*----------------------------------------------------------------------*
*       INTERFACE account
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
INTERFACE account.
   METHODS calc .
   DATA balance TYPE i.
ENDINTERFACE.                    "account

*----------------------------------------------------------------------*
*       CLASS CLS1 DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS cls1 DEFINITION.
   PUBLIC SECTION.
    INTERFACES account.
*      ALIASES calc FOR account~write_status.

ENDCLASS.                    "CLS1 DEFINITION

*----------------------------------------------------------------------*
*       CLASS CLS1 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS cls1 IMPLEMENTATION.
   METHOD account~calc.
    WRITE : / 'Deposit money is : ', account~balance.
ENDMETHOD.                    "account~calc
ENDCLASS.                    "CLS1 IMPLEMENTATION

*----------------------------------------------------------------------*
*       CLASS CLS2 DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*

CLASS cls2 DEFINITION.
   PUBLIC SECTION.
    INTERFACES account.
*      ALIASES calc FOR account~write_status.

ENDCLASS.                    "CLS2 DEFINITION

*----------------------------------------------------------------------*
*       CLASS CLS2 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS cls2 IMPLEMENTATION.
   METHOD account~calc.
    WRITE : / 'Withdrawl money is : ', account~balance.
ENDMETHOD.                    "account~calc
ENDCLASS.                    "CLS2 IMPLEMENTATION


DATA : cref1 TYPE REF TO cls1,
       cref2 TYPE REF TO cls2,
       iref  TYPE REF TO account.

START-OF-SELECTION.

   CREATE OBJECT : cref1, cref2.

  cref1->account~balance = 300.
   CALL METHOD: cref1->account~calc.

  iref = cref1.
  CALL METHOD iref->calc.

  cref2->account~balance = '-200'.
   CALL METHOD: cref2->account~calc.

  iref = cref2.
  CALL METHOD iref->calc.