In SAP ABAP, pass by value and pass by reference are two methods of passing data to methods, function modules, or forms. They determine how the data is handed over and whether changes to the data affect the original variable.
| Aspect | Pass by Value | Pass by Reference |
|---|---|---|
| Memory | More (copies data) | Less (passes reference) |
| Speed | Slower | Faster |
| Original Changed? | No | Yes |
| Syntax | VALUE(...) | Default or REFERENCE(...) |
REPORT zrep_lclclass.
DATA: lv_val TYPE i VALUE 5,
lv_ref TYPE i VALUE 5.
CLASS zcl_pass_test DEFINITION.
PUBLIC SECTION.
METHODS:
pass_by_value IMPORTING value(iv_num) TYPE i,
pass_by_ref CHANGING cv_num TYPE i.
ENDCLASS.
CLASS zcl_pass_test IMPLEMENTATION.
METHOD pass_by_value.
iv_num = iv_num + 10.
WRITE: / 'Inside pass_by_value: ', iv_num.
ENDMETHOD.
METHOD pass_by_ref.
cv_num = cv_num + 10.
WRITE: / 'Inside pass_by_ref: ', cv_num.
ENDMETHOD.
ENDCLASS.
START-OF-SELECTION.
DATA(lo_pass_test) = NEW zcl_pass_test( ).
WRITE: / 'Before pass_by_value: ', lv_val.
lo_pass_test->pass_by_value( iv_num = lv_val ).
WRITE: / 'After pass_by_value: ', lv_val. " Unchanged
SKIP.
WRITE: / 'Before pass_by_ref: ', lv_ref.
lo_pass_test->pass_by_ref( CHANGING cv_num = lv_ref ).
WRITE: / 'After pass_by_ref: ', lv_ref. " Changed Output:
