Just copy and paste the code. It will work .
DATA: BEGIN OF ls_data,
data TYPE char5,
END OF ls_data.
DATA : lt_data LIKE TABLE OF ls_data,
lv_cons(5) TYPE c VALUE 'XYXYX',
lv_cony(5) TYPE c VALUE 'YXYXY',
count TYPE sy-tabix,
flag TYPE flag,
count1 TYPE sy-tabix,
count2 TYPE sy-tabix.
ls_data-data = 'xyxyx'.
APPEND ls_data TO lt_data.
*count = strlen(ls_data-data).
DESCRIBE FIELD lv_cons LENGTH count.
LOOP AT lt_data INTO ls_data.
WRITE : / ls_data-data.
count = count - 1.
count1 = 5 - count.
IF count = 0.
EXIT.
ENDIF.
ls_data-data = lv_cons+count1(count).
APPEND ls_data TO lt_data.
ENDLOOP.
REFRESH: lt_data.
CLEAR: count,count1,count2,lt_data,ls_data.
ls_data-data = 'YXYXY'.
APPEND ls_data TO lt_data.
*count = strlen(ls_data-data).
DESCRIBE FIELD lv_cony LENGTH count.
LOOP AT lt_data INTO ls_data.
count1 = count - 1.
count = count1.
count2 = 5 - count.
ls_data-data = lv_cony+count1(count2).
APPEND ls_data TO lt_data.
WRITE : / ls_data-data.
IF count2 EQ 5.
EXIT.
ENDIF.
ENDLOOP.