Modification not working for both internal table and control table in SAP ABAP

There seems to some mistake in your update modle. PFB the updated one

Example

MODULE update INPUT.  
    MODIFY snctab INDEX ctrl-current_line.
    IF sy-subrc <> 0.
       APPEND snctab.
    ENDIF.
 ENDMODULE.

SAP ABAP Expert

Published on 25-Dec-2017 17:52:16