Abap oo concepts

Question

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.

Answer 1

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