Move a variable to a component of a field-symbol structure ???

Question

I have a field symbol <fs_struc> that's typed as a structure from the dictionary.
I want to move a variable to a particular component of this structure, and I've put the name of his component in another field symbol <fs_comp>.
1) Why doesn't the following syntax work?
ASSIGN variable TO <fs_struc>-<fs_comp>
(Note that there's a hyphen between <fs_struc> and <fs_comp>)
2) What is the correct syntax to do this ?
Thanks.

Answer 1

Hi David,
1) If you've assigned <fs_comp> to a field in a structure, then you have the memory address of the component within the structure.  This is why the syntax does not work, because <fs_comp> contains the reference already to the structure (eg. <fs_comp> =  structure-field, while <fs_field>-<fs_comp> =  structure-structure-field).  You can instead use:
ASSIGN variable TO <fs_comp>, if <fs_comp> was already assigned to a field of a structure.
2) If your scenario is that you don't know the field of the structure you want to assign in advance, you can try something like the following.  Snippet just shows how you can dynamically assign a field of a structure to another field symbol.
data: ls_kna1 type kna1.
data: lv_comp_name(5) type c value 'NAME1'.
data: o_data type ref to data.
field-symbols: <fs_data> type kna1.
field-symbols: <fs_comp> type any.
ls_kna1-name1 = 'Testing'.
CREATE DATA o_data TYPE (lv_comp_name).
      ASSIGN o_data->* TO <fs_comp>.
assign ls_kna1 to <fs_data>.
ASSIGN COMPONENT lv_comp_name OF STRUCTURE <fs_data> TO <fs_comp>.
write: <fs_comp>