OO ABAP - Optional & preferred parameters in methods

*&---------------------------------------------------------------------*
*& Report  YSAP_CLASS_OPTIONAL
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT  ysap_class_optional.

*----------------------------------------------------------------------*
*       CLASS C1 DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class1 DEFINITION.
  PUBLIC SECTION.
    METHODS : method1 IMPORTING input1 TYPE i OPTIONAL
                                input2 TYPE i OPTIONAL
    PREFERRED PARAMETER input2.
ENDCLASS.                    "C1 DEFINITION
*----------------------------------------------------------------------*
*       CLASS C1 IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS class1 IMPLEMENTATION.
  METHOD : method1.
    WRITE:/5 input1 ,
          /5 input2 .
  ENDMETHOD.                    ":
ENDCLASS.                    "C1 IMPLEMENTATION

START-OF-SELECTION.
  DATA : object1 TYPE REF TO class1.
  CREATE OBJECT : object1.
  CALL METHOD : object1->method1( input1 = 9 input2 = 7 ).
  SKIP 2.
  WRITE:/5 'Next call'.
  CALL METHOD object1->method1( 10 ) .