ABAP 求和字段

*&---------------------------------------------------------------------*
*& Report ZDEMO02
*&---------------------------------------------------------------------*
*&
*&---------------------------------------------------------------------*
REPORT zdemo02.

DATA:BEGIN OF gs_itab,
       m1 TYPE i VALUE 0,
       c1 TYPE i VALUE 1,
       c2 TYPE i VALUE 2,
       c3 TYPE i VALUE 3,
       c4 TYPE i VALUE 4,
       sum TYPE i,
     END OF gs_itab.

FIELD-SYMBOLS <fv_i> TYPE any.
DO 4 TIMES.
  ASSIGN COMPONENT |C{ sy-index }| OF STRUCTURE gs_itab TO <fv_i>.

  ADD <fv_i> TO gs_itab-sum.
  UNASSIGN <fv_i>.
ENDDO.

DATA:gv_i TYPE i.
DO 4 TIMES VARYING gv_i FROM gs_itab-c1 NEXT  gs_itab-c2.
  ADD gv_i TO gs_itab-sum.
ENDDO.