*&---------------------------------------------------------------------*
*& This code snippet implements the local calss ANIMAL and LION
*&---------------------------------------------------------------------*
REPORT ztest_narrow_casting.
*
*----------------------------------------------------------------------*
* Animal Super Class defintion
*----------------------------------------------------------------------*
CLASS lcl_animal DEFINITION.
PUBLIC SECTION.
METHODS: hungry.
ENDCLASS. "lcl_animal DEFINITION
*
*----------------------------------------------------------------------*
* Lion subclass defintion
*----------------------------------------------------------------------*
CLASS lcl_lion DEFINITION INHERITING FROM lcl_animal.
PUBLIC SECTION.
METHODS: hungry REDEFINITION,
fasting.
ENDCLASS. "lcl_lion DEFINITION
*
*
*----------------------------------------------------------------------*
* Animal Implementation
*----------------------------------------------------------------------*
CLASS lcl_animal IMPLEMENTATION.
METHOD hungry.
WRITE: / 'An animal is hungry'.
ENDMETHOD. "hungry
ENDCLASS. "lcl_animal IMPLEMENTATION
*
*----------------------------------------------------------------------*
* Lion subclass implementation
*----------------------------------------------------------------------*
CLASS lcl_lion IMPLEMENTATION.
METHOD hungry.
WRITE: / 'A Lion (King of Jungle) is hungry.',
'Run as fast as you can..!'.
ENDMETHOD. "hungry
METHOD fasting.
WRITE: / 'Stop running. Lion is on Fasting today.'.
ENDMETHOD.
ENDCLASS. "lcl_lion IMPLEMENTATION
*----------------------------------------------------------------------*
* This code shows how to use the Narrow casting
*----------------------------------------------------------------------*
START-OF-SELECTION.
DATA: lo_animal TYPE REF TO lcl_animal,
lo_lion TYPE REF TO lcl_lion.
*
* ANIMAL object without NARROW casting
WRITE: / 'Animal - without NARROW casting'.
CREATE OBJECT lo_animal.
CALL METHOD lo_animal->hungry( ).
CLEAR lo_animal.
*
* ANIMAL object with NARROW CASTING
SKIP 2.
WRITE: / 'Animal - NARROW casting from LION'.
CREATE OBJECT lo_lion.
lo_animal = lo_lion.
CALL METHOD lo_animal->hungry( ).
*
* call the method FASTING must be a dynamic because FASTING is not
* in the Animal
CALL METHOD lo_animal->('FASTING').
my program is going dump as shown in the following picture:
