CLEAR、REFRESH、FREE功能对比:
clear itab,仅清空HEADER LINE,对内表数据存储空间不影响,保留内存区。
clear itab[],清空内表数据存储空间里的内容。
refresh itab,不清空HEADER LINE,清除内表数据存储空间,但保存内存区。
free itab,不清空HEADER LINE,清空内表数据存储空间。
例子:
REPORT ZZZZZZZZZ.
types:begin of head, mantr(10) type c, id(10) type c, end of head. data gt_head type table of head with header line.
gt_head-mantr = 'wo'. gt_head-id = '00001'. append gt_head.
gt_head-mantr = 'you'. gt_head-id = '00002'. append gt_head.
free gt_head. write:gt_head.
loop at gt_head. write: / gt_head. endloop.
gt_head-mantr = 'he'. gt_head-id = '00003'. append gt_head. write:gt_head.