Pointers in ABAP

Question

hello all,
can any one plz tell me what are pointers in ABAP n how they can be used in report?
thanks for help.
regards,
vikas

Answer 1

in ABAP Pointers call as Field symbols and see the example programs :
REPORT CHAP2401.
Defining a Field Symbol
FIELD-SYMBOLS <FS>.
Variable for later use
DATA FIELD VALUE 'X'.
Assigning a field to a Field Symbol
ASSIGN FIELD TO <FS>.
Using a Field Symbol which has an assigned field
WRITE <FS>.
Another one :
REPORT zfield_symbols .
TYPES: BEGIN OF t_p0121,
pernr TYPE pa0121-pernr,
rfp01 TYPE pa0121-rfp01,
rfp02 TYPE pa0121-rfp02,
rfp03 TYPE pa0121-rfp03,
rfp04 TYPE pa0121-rfp04,
END OF t_p0121.
DATA: it_p0121 TYPE STANDARD TABLE OF t_p0121 INITIAL SIZE 0,
wa_p0121 TYPE t_p0121.
DATA: gd_index TYPE string,
gd_rfp0 TYPE string.
FIELD-SYMBOLS: <fs1>, <fs2>.
*Start-of-selection.
START-OF-SELECTION.
SELECT pernr
rfp01
rfp02
rfp03
rfp04
UP TO 10 ROWS
FROM pa0121
INTO TABLE it_p0121.
*End-of-selection.
END-OF-SELECTION.
WA_P0121-RFP01 = '1234'.
CONCATENATE 'WA_P0121-RFP01' gd_index INTO gd_rfp0.
Now watch how the values change as you loop around the table fields
LOOP AT it_p0121 INTO wa_p0121.
write:/.
write:/ wa_p0121-pernr.
CLEAR: gd_index.
DO.
gd_index = gd_index + 1.
CONCATENATE 'WA_P0121-RFP0' gd_index INTO gd_rfp0.
assign with brackets
ASSIGN (gd_rfp0) TO <fs1>. "assigns the value of field name contained in variable
fs1 value would be the value of the field WA_P0121-RFP01..21
i.e. if index 1 and WA_P0121-RFP01 = 1234 then fs1 would = 1234
assign without brackets
ASSIGN gd_rfp0 TO <fs2>. " assigns the exact value contained in the field
fs1 value would literally be the same as the field WA_P0121-RFP01..21
i.e. if index 1 then fs2 would = 'WA_P0121-RFP01'
index 2 then fs2 would = 'WA_P0121-RFP02' etc...
you may also notice that once assigned any change made to the field gd_rfp0
is instantly reflected in the field symbol (fs2) so technically you could perform
the assign command once outside of the loop, but i have left it here to aid
readability.
write:/ <fs2>, <fs1>.
IF gd_index GE 21. "exit once last field has been read
EXIT.
ENDIF.
ENDDO.
ENDLOOP.
Thanks
Seshu