Describe field, structure, table, ddic object

 form set_header using  iv_delim type char1  
          changing es_header type string.  
   
  data: lv_ddobj type ddobjname value 'ZPWORKDAY_EXTRACT'.  
  data: lt_str type standard table of dfies.  
  field-symbols: <str> type dfies.  
   
  call function 'DDIF_FIELDINFO_GET' "to get structure field details  
   exporting  
    tabname    = lv_ddobj  
   tables  
    dfies_tab   = lt_str  
   exceptions  
    not_found   = 1  
    internal_error = 2  
    others     = 3.  
   
  loop at lt_str assigning <str>.  
   if es_header is initial.  
    es_header = <str>-fieldtext.  
   else.  
    concatenate es_header iv_delim <str>-fieldtext into es_header.  
   endif.  
  endloop.  
   
 endform.          " SET_HEADER     
 

DATA: lv TYPE fmglflexa.  
   
 DATA: typ1,  
    comp1 TYPE i,  
    typ2,  
    comp2 TYPE i.  
 DATA: td    TYPE sydes_desc.  
   
 DESCRIBE FIELD lv TYPE typ1 COMPONENTS comp1.  
 DESCRIBE FIELD lv INTO td.