How to update internal table without using MODIFY?

Question

I have created internal tables where I want to update age of employee in one internal table by calculating it from another table, I have done arithmetic calculations to get age but now how can I update it by any alternate way instead of MODIFY?

WRITE : / 'FirstName','LastName', '  Age'.  
LOOP AT gt_items1 INTO gwa_items1.
  READ TABLE gt_header INTO gwa_header WITH KEY empid = gwa_items1-empid.
  gwa_items1-age = gv_date+0(4) - gwa_header-bdate+0(4).
        
  MODIFY gt_items1 from gwa_items1 TRANSPORTING age WHERE empid = gwa_items1-empid.
  WRITE : /  gwa_items1-fname , gwa_items1-lname , gwa_items1-age .
ENDLOOP.

Answer 1

Use field symbols (instead of work areas) by LOOPing over internal tables:

WRITE : / 'FirstName','LastName', '  Age'.  
LOOP AT gt_items1 
     ASSIGNING FIELD-SYMBOL(<ls_item1>).
  READ TABLE gt_header 
       ASSIGNING FIELD-SYMBOL(<ls_header>) 
       WITH KEY empid = <ls_item1>-empid.
  IF sy-subrc EQ 0.
    <ls_item1>-age = gv_date+0(4) - <ls_header>-bdate+0(4).
    WRITE : /  <ls_item1>-fname , <ls_item1>-lname , <ls_item1>-age .
  ENDIF.
ENDLOOP.

Field symbols have two advantages:

• They modify the internal table directly, no separate MODIFY is necessary.

• They are somewhat faster, than work areas.