*&---------------------------------------------------------------------*
*& Report  ZABAP101_RECURSION
*&
*&---------------------------------------------------------------------*
*&
*&
*&---------------------------------------------------------------------*

REPORT  zabap101_recursion.

*----------------------------------------------------------------------*
*       CLASS lcl_math DEFINITION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS lcl_math DEFINITION.

  PUBLIC SECTION.

    METHODS execute_exponentiation
              IMPORTING
                base TYPE i
                expoent TYPE i
              RETURNING value(re_power) TYPE i.

  PRIVATE SECTION.

    DATA: interaction TYPE i,
          power       TYPE i VALUE 1.

ENDCLASS.                    "lcl_math DEFINITION


*----------------------------------------------------------------------*
*       CLASS lcl_math IMPLEMENTATION
*----------------------------------------------------------------------*
*
*----------------------------------------------------------------------*
CLASS lcl_math IMPLEMENTATION.

  METHOD execute_exponentiation.
    ADD 1 TO interaction.
    IF interaction <= expoent.
      power = me->execute_exponentiation( base = base
                                          expoent = expoent ).
      MULTIPLY power BY base.
    ENDIF.
    re_power = power.
  ENDMETHOD.                    "execute_exponentiation

ENDCLASS.                    "lcl_math IMPLEMENTATION

DATA: r_exp   TYPE REF TO lcl_math,
      v_power TYPE i.

PARAMETERS: p_base TYPE i DEFAULT 2,
            p_exp  TYPE i DEFAULT 3,
            p_rec  AS CHECKBOX.

INITIALIZATION.

  CREATE OBJECT r_exp.

START-OF-SELECTION.

  IF p_rec = 'X'.
    v_power = r_exp->execute_exponentiation( base = p_base
                                             expoent = p_exp ).
  ELSE.
    v_power = p_base ** p_exp.
  ENDIF.

  WRITE: / 'Power: ', v_power.