How to pass an object as method parameter

Question

Hi Guys
I was testing a simple program and was trying to pass an object to a method but it didnt seem to work and I couldnt find out WHY.
I am posting the code so please let me know who can i make my method ADD_EMPLOYEE work so that when i pass an object of LCL_EMPLOYEE, it updates I_EMPLOYEE_LIST.
*& Report:  ZOO_HR_SAMPLE_1
*& Author:  Avinash Pandey
*& Date:    25.03.2009
*& Description: Concepts of OO in ABAP
REPORT  zoo_hr_sample_1.
*&       Class LCL_EMPLOYEE
       Local class
CLASS lcl_employee DEFINITION.
Public section
  PUBLIC SECTION.
Data type
    TYPES:
      BEGIN OF t_employee,
        no  TYPE i,
        name TYPE string,
        wage TYPE i,
     END OF t_employee.
Method
    METHODS:
      constructor
        IMPORTING im_employee_no TYPE i
                  im_employee_name TYPE string
                  im_wage TYPE i,
        add_employee
         IMPORTING im_employee TYPE REF TO lcl_employee,
       display_employee_list,
       display_employee,
       get_no EXPORTING ex_no TYPE i,
       get_name EXPORTING ex_name TYPE string,
       get_wage EXPORTING ex_wage TYPE i.
  Class methods are global for all instances
    CLASS-METHODS: display_no_of_employees.
Protected section
  PROTECTED SECTION.
  Class data are global for all instances
    CLASS-DATA: g_no_of_employees TYPE i.
    CLASS-DATA: i_employee_list TYPE TABLE OF t_employee.
Private section
  PRIVATE SECTION.
   CLASS-DATA: i_employee_list TYPE TABLE OF t_employee.
    DATA: g_employee TYPE t_employee.
ENDCLASS.               "LCL_EMPLOYEE
*&       Class (Implementation)  LCL_EMPLOYEE
       Text
CLASS lcl_employee IMPLEMENTATION.
Class constructor method
  METHOD constructor.
    g_employee-no = im_employee_no.
    g_employee-name = im_employee_name.
    g_employee-wage = im_wage.
    g_no_of_employees = g_no_of_employees + 1.
  ENDMETHOD.                    "constructor
Method
  METHOD display_employee.
    WRITE:/ 'Employee', g_employee-no, g_employee-name.
  ENDMETHOD.                    "display_employee
Method
  METHOD get_no.
    ex_no = g_employee-no.
  ENDMETHOD.                    "get_no
Method
  METHOD get_name.
    ex_name = g_employee-name.
    WRITE: / 'Name is:' , ex_name.
  ENDMETHOD.                    "get_no
Method
  METHOD get_wage.
    ex_wage = g_employee-wage.
  ENDMETHOD.                    "get_no
Method
  METHOD add_employee.
  Adds a new employee to the list of employees
    DATA: l_employee TYPE t_employee.
    l_employee-no = im_employee->get_no.
    l_employee-name = im_employee->get_name.
    l_employee-wage = im_employee->get_wage.
    APPEND l_employee TO i_employee_list.
  ENDMETHOD.                    "add_employee
Method
  METHOD display_employee_list.
  Displays all employees and there wage
    DATA: l_employee TYPE t_employee.
    WRITE: / 'List of Employees'.
    LOOP AT i_employee_list INTO l_employee.
      WRITE: / l_employee-no, l_employee-name, l_employee-wage.
    ENDLOOP.
  ENDMETHOD.                    "display_employee_list
Class method
  METHOD display_no_of_employees.
    WRITE: / 'Number of employees is:', g_no_of_employees.
  ENDMETHOD.                    "display_no_of_employees
ENDCLASS.               "LCL_EMPLOYEE
REPORT
DATA: g_employee1 TYPE REF TO lcl_employee,
      g_employee2 TYPE REF TO lcl_employee.
START-OF-SELECTION.
Create class instances
  CREATE OBJECT g_employee1
    EXPORTING
      im_employee_no   = 1
      im_employee_name = 'John Jones'
      im_wage          = 20000.
  CREATE OBJECT g_employee2
    EXPORTING
      im_employee_no   = 2
      im_employee_name = 'Sally Summer'
      im_wage          = 28000.
Call methods
  CALL METHOD g_employee1->display_employee.
  CALL METHOD g_employee1->add_employee
    EXPORTING
      im_employee = g_employee1.
  CALL METHOD g_employee1->get_name.
  CALL METHOD g_employee2->display_employee.
  CALL METHOD g_employee2->display_no_of_employees.
The error I am getting is:
Field GET_NO/GET_NAME/GET_WAGE is unknown.
Please help me out on this.
Thanks a lot you people

Answer 1

hi.
The following parts of your program were changed.
The result is OK?.
*(1)change
CLASS lcl_employee DEFINITION.
Public section
PUBLIC SECTION.
display_employee,
*get_no EXPORTING ex_no TYPE i,
*get_name EXPORTING ex_name TYPE string,
*get_wage EXPORTING ex_wage TYPE i.
get_no returning value(ex_no) TYPE i,
get_name returning value(ex_name) TYPE string,
get_wage returning value(ex_wage) TYPE i.
*(2)change
CLASS lcl_employee IMPLEMENTATION.
Method
METHOD add_employee.
Adds a new employee to the list of employees
DATA: l_employee TYPE t_employee.
*l_employee-no = im_employee->get_no.
*l_employee-name = im_employee->get_name.
*l_employee-wage = im_employee->get_wage.
l_employee-no   = im_employee->get_no( ).
l_employee-name = im_employee->get_name( ).
l_employee-wage = im_employee->get_wage( ).
APPEND l_employee TO i_employee_list.
ENDMETHOD. "add_employee
Result List
Employee          1  John Jones
Name is: John Jones
Name is: John Jones
Employee          2  Sally Summer
Number of employees is:          2