Übung Schrödinger: 09 Vererbung (ABAP)

Beispiellisting für Vererbung in lokalen Klassen aus Kapitel 09 im Buch Schrödinger programmiert ABAP.

<syntaxhighight lang="abap"> REPORT zsch_matt_beer.

CLASS lcl_bier DEFINITION.

 PUBLIC SECTION.
   DATA: gd_stammwuerze TYPE p LENGTH 3 DECIMALS 2 VALUE '12.50'.
   TYPES: gdt_alkoholgehalt LIKE gd_stammwuerze.
   METHODS: write_stammwuerze,
            write_volumen,
            set_alkoholgehalt
            IMPORTING id_alkoholgehalt TYPE gdt_alkoholgehalt,
            brauen.
 PROTECTED SECTION.
   DATA: gd_volumen TYPE p LENGTH 4 DECIMALS 2 VALUE 333.
 PRIVATE SECTION.
   DATA: gd_alkoholgehalt TYPE gdt_alkoholgehalt VALUE '4.50'.

ENDCLASS.

CLASS lcl_bier IMPLEMENTATION.

 METHOD write_stammwuerze.
   WRITE:  / `Stammwürze: `, me->gd_stammwuerze.
 ENDMETHOD.

 METHOD write_volumen.
   WRITE:  / `Volumen: `, me->gd_volumen.
 ENDMETHOD.

 METHOD set_alkoholgehalt.
   me->gd_alkoholgehalt = id_alkoholgehalt.
 ENDMETHOD.

 METHOD brauen.
   WRITE: / 'Ich braue und braue Bier den ganzen lieben langen Tag.'.
 ENDMETHOD.

ENDCLASS.

CLASS lcl_bier_untergaerig DEFINITION INHERITING FROM lcl_bier.

 PUBLIC SECTION.
   METHODS: brauen REDEFINITION.
 PROTECTED SECTION.
 PRIVATE SECTION.

ENDCLASS.

CLASS lcl_bier_untergaerig IMPLEMENTATION.

 METHOD brauen.
   CALL METHOD super->brauen.
   WRITE: / 'Sogar untergärig'.
 ENDMETHOD.

ENDCLASS.

CLASS lcl_koelsch DEFINITION INHERITING FROM lcl_bier.

 PUBLIC SECTION.
 PROTECTED SECTION.
 PRIVATE SECTION.

ENDCLASS.

CLASS lcl_koelsch IMPLEMENTATION. ENDCLASS.

DATA: gr_untergaerig TYPE REF TO lcl_bier_untergaerig.

START-OF-SELECTION.

 CREATE OBJECT gr_untergaerig.
 CALL METHOD gr_untergaerig->write_stammwuerze.
 CALL METHOD gr_untergaerig->write_volumen.
 CALL METHOD gr_untergaerig->brauen.

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