如果有abcd，at end of B，是对B以及B之前的字段进行判断
不是仅仅对b进行判断，而且如果at end of b，就会对b后面的数据清空初始化，
所以在at end of 前用 另一个工作区接收一下，
一定注意，是B之前的所有字段进行判断
at new也一样
例子：
REPORT
zlm_at_end_of.
TYPES: BEGIN OF ty_itab,
a TYPE i,
b TYPE i,
c TYPE decfloat34,
d TYPE i,
e TYPE i,
END OF ty_itab.
DATA:d TYPE i.
DATA: wa_itab TYPE ty_itab,
it_itab LIKE STANDARD TABLE OF wa_itab.
DATA: wa_itab2 TYPE ty_itab,
it_itab2 LIKE STANDARD TABLE OF wa_itab2.
wa_itab-a = 1.
wa_itab-b = 2.
wa_itab-c = 3.
wa_itab-d = 4.
wa_itab-e = 5.
APPEND wa_itab TO it_itab.
CLEAR:wa_itab.
wa_itab-a = 1.
wa_itab-b = 2.
wa_itab-c = 8.
wa_itab-d = 9.
wa_itab-e = 10.
APPEND wa_itab TO it_itab.
CLEAR:wa_itab.
wa_itab-a = 1
.
wa_itab-b = 2.
wa_itab-c = 13.
wa_itab-d = 14.
wa_itab-e = 15.
APPEND wa_itab TO it_itab.
CLEAR:wa_itab.
wa_itab-a = 12.
wa_itab-b = 3.
wa_itab-c = 13.
wa_itab-d = 14.
wa_itab-e = 15.
APPEND wa_itab TO it_itab.
CLEAR:wa_itab.
REFRESH it_itab2.
LOOP AT it_itab INTO wa_itab.
AT END OF b.
WRITE : / wa_itab-a,wa_itab-b,wa_itab-c.
ULINE.
ENDAT.
ENDLOOP.
特别注意： at end of 或者new of
后，
of参考字段后面的所有字段都会 被清空 有时候是变成 *
（星号）。
使用时特别注意，是否使用of 后面的字段了
