When a subclass contains new components which are not declared in the superclass then calling the new components by creating a dynamic reference of superclass will cause the syntax error in the system.

Here we have defined a parent class and a child class inheriting from the parent class. In the parent class, we have declared a method m_par. And in the child class, we have redefined the method m_par and a new method m_chi. Now we have declared the object obj_par referenced by parent and object obj_chi referenced by child statically. At the time of object creation, we have referenced obj_par of type child by dynamically. Now, whenever we call the method m_chi by obj_par then the syntax error will come. Here the error comes because the method m_chi is unknown to parent class though obj_par is dynamically referenced to the child class. Hence the superclass object obj_par has found the method m_chi a new component which is not declared in the superclass.

*&---------------------------------------------------------------------*
*& Report  ZSR_TEST
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT  zsr_test.

*----------------------------------------------------------------------*
*       CLASS parent DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS parent DEFINITION.
  PUBLIC SECTION.
    DATA v_txt TYPE char50.
    METHODS m_par.
ENDCLASS.                    "parent DEFINITION

*----------------------------------------------------------------------*
*       CLASS child DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS child DEFINITION INHERITING FROM parent.
  PUBLIC SECTION.
    METHODS m_par REDEFINITION.
    METHODS m_chi.
ENDCLASS.                    "child DEFINITION

*----------------------------------------------------------------------*
*       CLASS parent IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS parent IMPLEMENTATION.
  METHOD m_par.
    v_txt = 'Parent Class Method'.
    WRITE / v_txt.
  ENDMETHOD.                    "m_par
ENDCLASS.                    "parent IMPLEMENTATION

*----------------------------------------------------------------------*
*       CLASS child IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS child IMPLEMENTATION.
  METHOD m_par.
    v_txt = 'Parent Class Method from Child Class'.
    WRITE / v_txt.
  ENDMETHOD.                    "m_par

  METHOD m_chi.
    v_txt = 'Child Class Method'.
    WRITE / v_txt.
  ENDMETHOD.                    "m_chi
ENDCLASS.                    "child IMPLEMENTATION

START-OF-SELECTION.
  DATA: obj_par TYPE REF TO parent, "Static Type
        obj_chi TYPE REF TO child.  "Static Type

  CREATE OBJECT obj_par.
  CALL METHOD   obj_par->m_par. "Call the method from Parent class
  SKIP.

  CREATE OBJECT: obj_par TYPE child,
                 obj_chi.
  CALL METHOD:   obj_par->m_par, "Call the Redefinition of m_par
                 obj_chi->m_chi.