ABAP Performance Examples

 *modifying a set of lines directly（批量修改内表数据）
 *使用"LOOP ... ASSIGNING ..."可以直接修改内表中的数据，而不需要先将内表数据复制到相应工作区，然后再更新回去。
 ***METHOD ONE:
 LOOP AT itab INTO wa.
   i = sy-tabix MOD .
   IF i = .
     wa-flag = 'X'.
     MODIFY itab FROM wa.
   ENDIF.
 ENDLOOP.

 ***METHOD TWO:
 field-symboles:<wa> like itab.
 LOOP AT itab ASSIGNING <wa>.
   i = sy-tabix MOD .
   IF i = .
     <wa>-flag = 'X'.
   ENDIF.
 ENDLOOP.

 ***METHOD THERE:
 DATA: gt_list TYPE TABLE OF ty_list.
 FIELD-SYMBOLS <fs_list> TYPE ty_list.
 CASE <fs_list>-wbstk.
   WHEN 'C'.
     <fs_list>-status = icon_led_green.
   WHEN 'B'.
     <fs_list>-status = icon_led_yellow.
   WHEN 'A'.
     <fs_list>-status = icon_led_red.
 ENDCASE.
 ENDLOOP.