使用ABAP REDUCE關鍵字編寫的一個非遞歸階乘實現
*&---------------------------------------------------------------------* *& Report ZAPPEND *&---------------------------------------------------------------------* *& *&---------------------------------------------------------------------* REPORT zcd_functional_factorial. CLASS lcl_factorial DEFINITION. PUBLIC SECTION. METHODS factorial IMPORTING !n TYPE i RETURNING VALUE(result) TYPE i. ENDCLASS. CLASS lcl_factorial IMPLEMENTATION. METHOD factorial. result = COND i( WHEN n = 0 THEN 1 ELSE REDUCE i( INIT r = 1 FOR i = 1 THEN i + 1 WHILE i <= n NEXT r = r * i ) ). ENDMETHOD. ENDCLASS. START-OF-SELECTION. cl_demo_output=>display( NEW lcl_factorial( )->factorial( 9 ) ).
