topic Re: simple code,strange issue in Application Development and Automation Discussions

simple code,strange issue

daixiong_jiang3 — Tue, 19 Aug 2008 08:55:12 GMT

i write the following code in my Netweaver abap trival version to test the inheritance of object:

REPORT z_object.

CLASS zclass DEFINITION.

PUBLIC SECTION.

METHODS:m1,m2.

ENDCLASS. "zclass DEFINITION

CLASS zclass_sub DEFINITION INHERITING FROM zclass.

PUBLIC SECTION.

METHODS m2 REDEFINITION.

ENDCLASS. "ZCLASS_SUB DEFINITION

CLASS zclass IMPLEMENTATION.

METHOD m1.

CALL METHOD me->m2.

ENDMETHOD. "m1

METHOD m2.

MESSAGE 'hello world' TYPE 'I'.

ENDMETHOD. "m2

ENDCLASS. "zclass IMPLEMENTATION

CLASS zclass_sub IMPLEMENTATION.

METHOD m2.

MESSAGE 'WORLD HELLO' TYPE 'I'.

ENDMETHOD. "M2

ENDCLASS. "ZCLASS_SUB IMPLEMENTATION

DATA: ref1 TYPE REF TO zclass,

ref2 TYPE REF TO zclass_sub.

CREATE OBJECT:ref1,ref2.

then the error message says: the statement "CREATE OBJECT:ref1,ref2." is not accessible.

how does this happen and how can i correct it? thanks in advance.i checked everything but found there should be no errors.

Re: simple code,strange issue

Former Member — Tue, 19 Aug 2008 09:06:58 GMT

Hi,

When you are declaring Data i.e referenec variable just write

START-OF-SELECTION.

Check this


CLASS zclass DEFINITION.
PUBLIC SECTION.
METHODS:m1,m2.
ENDCLASS. "zclass DEFINITION

CLASS zclass_sub DEFINITION INHERITING FROM zclass.
PUBLIC SECTION.
METHODS m2 REDEFINITION.
ENDCLASS. "ZCLASS_SUB DEFINITION

CLASS zclass IMPLEMENTATION.
METHOD m1.
CALL METHOD me->m2.
ENDMETHOD. "m1
METHOD m2.
MESSAGE 'hello world' TYPE 'I'.
ENDMETHOD. "m2
ENDCLASS. "zclass IMPLEMENTATION

CLASS zclass_sub IMPLEMENTATION.
METHOD m2.
MESSAGE 'WORLD HELLO' TYPE 'I'.
ENDMETHOD. "M2
ENDCLASS. "ZCLASS_SUB IMPLEMENTATION

start-of-selection." -> Here**************

DATA: ref1 TYPE REF TO zclass,
ref2 TYPE REF TO zclass_sub.

CREATE OBJECT: ref1,ref2.

Regards,

Sujit

Re: simple code,strange issue

Former Member — Tue, 19 Aug 2008 09:15:59 GMT

Hii

Check this code


REPORT z_sdn.


CLASS zclass DEFINITION.
PUBLIC SECTION.
METHODS:m1,m2.
ENDCLASS. "zclass DEFINITION

CLASS zclass_sub DEFINITION INHERITING FROM zclass.
PUBLIC SECTION.
METHODS m2 REDEFINITION.
ENDCLASS. "ZCLASS_SUB DEFINITION

CLASS zclass IMPLEMENTATION.
METHOD m1.
CALL METHOD me->m2.
ENDMETHOD. "m1
METHOD m2.
MESSAGE 'hello world' TYPE 'I'.
ENDMETHOD. "m2
ENDCLASS. "zclass IMPLEMENTATION

CLASS zclass_sub IMPLEMENTATION.
METHOD m2.
MESSAGE 'WORLD HELLO' TYPE 'I'.
ENDMETHOD. "M2
ENDCLASS. "ZCLASS_SUB IMPLEMENTATION

DATA: ref1 TYPE REF TO zclass,
      ref2 TYPE REF TO zclass_sub.

START-OF-SELECTION.
CREATE OBJECT:ref1.

Regards

Abhijeet

Re: simple code,strange issue

daixiong_jiang3 — Tue, 19 Aug 2008 09:29:25 GMT

when i add the statement "START-OF-SELECTION." to the report it actually works.

another issue occurs:

REPORT z_object.

CLASS zclass DEFINITION.

PUBLIC SECTION.

METHODS:m1,m2.

ENDCLASS. "zclass DEFINITION

CLASS zclass_sub DEFINITION INHERITING FROM zclass.

PUBLIC SECTION.

METHODS m2 REDEFINITION.

ENDCLASS. "ZCLASS_SUB DEFINITION

CLASS zclass IMPLEMENTATION.

METHOD m1.

CALL METHOD me->m2.

ENDMETHOD. "m1

METHOD m2.

MESSAGE 'hello world' TYPE 'I'.

ENDMETHOD. "m2

ENDCLASS. "zclass IMPLEMENTATION

CLASS zclass_sub IMPLEMENTATION.

METHOD m2.

SUPER->M2.

MESSAGE 'WORLD HELLO' TYPE 'I'.

ENDMETHOD. "M2

ENDCLASS. "ZCLASS_SUB IMPLEMENTATION

START-OF-SELECTION.

DATA: ref1 TYPE REF TO zclass,

ref2 TYPE REF TO zclass_sub.

CREATE OBJECT:ref1,ref2.

The error message says: SUPER->M2 is not defined.

but in fact we can use the pseudoreference super-> to access the same superclass method in the redifinited method..

Edited by: Daixiong Jiang on Aug 19, 2008 5:29 PM

Re: simple code,strange issue

matt — Tue, 19 Aug 2008 09:38:00 GMT

Super-m2( ). You forgot the brackets. I do this all the time!

matt

Re: simple code,strange issue

Former Member — Tue, 19 Aug 2008 09:54:46 GMT

Hi,

Check the code you have written-I have changed-



CLASS zclass DEFINITION.
PUBLIC SECTION.
METHODS:m1,m2.
ENDCLASS. "zclass DEFINITION

CLASS zclass_sub DEFINITION INHERITING FROM zclass.
PUBLIC SECTION.
METHODS m2 REDEFINITION.
ENDCLASS. "ZCLASS_SUB DEFINITION

CLASS zclass IMPLEMENTATION.
METHOD m1.
CALL METHOD me->m2.
ENDMETHOD. "m1
METHOD m2.
MESSAGE 'hello world' TYPE 'I'.
ENDMETHOD. "m2
ENDCLASS. "zclass IMPLEMENTATION

CLASS zclass_sub IMPLEMENTATION.
METHOD m2.
SUPER->M2( ). "<----------------Here Brackets
MESSAGE 'WORLD HELLO' TYPE 'I'.
ENDMETHOD. "M2
ENDCLASS. "ZCLASS_SUB IMPLEMENTATION

START-OF-SELECTION.

DATA: ref1 TYPE REF TO zclass,
ref2 TYPE REF TO zclass_sub.

CREATE OBJECT:ref1,ref2.

Regards,

Sujit