abap oo concepts

[Former Member]

Hi,

I have used this code in my prog.I got "Cref is not an object reference" error..how to rectify it..please help if u know...

data:cref type ref to c1.

create object cref.

[former_member402443]

Hi Kavitha,

For this u have to create a class with name zaccountMA in the

se24 class builder

or u have to define it locally in your program.

check this code .

In this i define the class locally.

*********************************************************************

• L C L _ E M P L O Y E E

*********************************************************************

*---- LCL Employee - Definition

CLASS lcl_employee DEFINITION.

PUBLIC SECTION.

*----

---

• The public section is accesible from outside

*----

---

TYPES:

BEGIN OF t_employee,

no TYPE i,

name TYPE string,

END OF t_employee.

METHODS:

constructor

IMPORTING im_employee_no TYPE i

im_employee_name TYPE string,

display_employee.

• Class methods are global for all instances

CLASS-METHODS: display_no_of_employees.

PROTECTED SECTION.

*----

---

• The protecetd section is accesible from the class and its subclasses

*----

---

• Class data are global for all instances

CLASS-DATA: g_no_of_employees TYPE i.

PRIVATE SECTION.

*----

---

• The private section is only accesible from within the classs

*----

---

DATA: g_employee TYPE t_employee.

ENDCLASS. "lcl_employee DEFINITION

*--- LCL Employee - Implementation

CLASS lcl_employee IMPLEMENTATION.

METHOD constructor.

g_employee-no = im_employee_no.

g_employee-name = im_employee_name.

g_no_of_employees = g_no_of_employees + 1.

ENDMETHOD. "constructor

METHOD display_employee.

WRITE:/ 'Employee', g_employee-no, g_employee-name.

ENDMETHOD. "display_employee

METHOD display_no_of_employees.

WRITE: / 'Number of employees is:', g_no_of_employees.

ENDMETHOD. "display_no_of_employees

ENDCLASS. "lcl_employee IMPLEMENTATION

************************************************************************

• R E P O R T

*********************************************************************

DATA: g_employee1 TYPE REF TO lcl_employee,

g_employee2 TYPE REF TO lcl_employee.

START-OF-SELECTION.

CREATE OBJECT g_employee1

EXPORTING im_employee_no = 1

im_employee_name = 'John Jones'.

CREATE OBJECT g_employee2

EXPORTING im_employee_no = 2

im_employee_name = 'Sally Summer'.

CALL METHOD g_employee1->display_employee.

CALL METHOD g_employee2->display_employee.

CALL METHOD g_employee2->display_no_of_employees.

Regards

Manoj Kumar

[former_member402443]

Hi Kavitha,

Will you problem solved or not. if not please tell me.

Regards

Manoj Kumar

[Former Member]

my prog code is this..i am getting run time error .please chk and correct me.I got error in at selection screen statements.

parameters:add Radiobutton group RG1,

sub Radiobutton group RG1,

Multi Radiobutton group RG1,

Div Radiobutton group RG1.

Class c1 definition.

public section.

data:a type i,b type i,c type i.

methods:add importing a type i b type i exporting c type i,

sub importing a type i b type i exporting c type i,

multi importing a type i b type i exporting c type i,

div importing a type i b type i exporting c type i.

endclass.

class c1 implementation.

method add.

c = a + b.

endmethod.

method sub.

c = a - b.

endmethod.

method multi.

c = a * b.

endmethod.

method div.

c = a / b.

endmethod.

endclass.

start-of-selection.

data:a type i,

b type i.

data:c type i,

result type i.

data:cref type ref to c1.

create object cref .

At selection-screen.

If add = 'X'.

call method cref->add exporting a = 10 b = 5 .

elseif sub = 'x'.

call method cref->sub exporting a = 10 b = 5 .

elseif multi = 'x'.

call method cref->multi exporting a = 10 b = 5 .

elseif div = 'x'.

call method cref->div exporting a = 10 b = 5 .

endif.

write:c.

[former_member402443]

Hi Kavitha,

Now i have modified your program little bit.

Now its working fine.Check it.

DATA oref TYPE REF TO cx_root.

DATA text TYPE string.

PARAMETERS:add RADIOBUTTON GROUP rg1,

sub RADIOBUTTON GROUP rg1,

multi RADIOBUTTON GROUP rg1,

div RADIOBUTTON GROUP rg1.

----

---

• CLASS c1 DEFINITION

----

---

*

----

---

CLASS c1 DEFINITION.

PUBLIC SECTION.

• DATA:a TYPE i,b TYPE i,c TYPE i.

METHODS: add IMPORTING a TYPE i

b TYPE i

RETURNING value(c) TYPE i.

METHODS: sub IMPORTING a TYPE i

b TYPE i

RETURNING value(c) TYPE i.

METHODS: multi IMPORTING a TYPE i

b TYPE i

RETURNING value(c) TYPE i.

METHODS: div IMPORTING a TYPE i

b TYPE i

RETURNING value(c) TYPE i.

ENDCLASS. "c1 DEFINITION

----

---

• CLASS c1 IMPLEMENTATION

----

---

*

----

---

CLASS c1 IMPLEMENTATION.

METHOD add.

c = a + b.

ENDMETHOD. "add

METHOD sub.

c = a - b.

ENDMETHOD. "sub

METHOD multi.

c = a * b.

ENDMETHOD. "multi

METHOD div.

c = a / b.

ENDMETHOD. "div

ENDCLASS. "c1 IMPLEMENTATION

START-OF-SELECTION.

DATA :result TYPE i.

DATA:cref TYPE REF TO c1.

CREATE OBJECT cref .

TRY.

IF add = 'X'.

CALL METHOD cref->add

EXPORTING

a = 10

b = 5

RECEIVING

c = result.

ELSEIF sub = 'X'.

CALL METHOD cref->sub

EXPORTING

a = 10

b = 5

RECEIVING

c = result.

ELSEIF multi = 'X'.

CALL METHOD cref->multi

EXPORTING

a = 10

b = 5

RECEIVING

c = result.

ELSEIF div = 'X'.

CALL METHOD cref->div

EXPORTING

a = 10

b = 5

RECEIVING

c = result.

ENDIF.

CATCH cx_root INTO oref. "Here i am catching an exception

text = oref->get_text( ).

ENDTRY.

IF NOT text IS INITIAL.

WRITE / text.

ELSE.

WRITE:result.

ENDIF.

Reward Points, if useful.

Regards,

Manoj Kumar

[Former Member]

Hi,

Thank you very much Manoj...................