ABAP’s – ‘Tips’ and ‘Traps’ alongwith New syntax

Hi Community,

Powered by the continuous thrust on self growth, I ventured upon using the new programming syntax in ABAP. Along the way I learnt some tips and tricks and discovered few shortcomings as well.  Through this post I would like to present a gist of this journey based on my experiments. Also, thanks to Jeffrey Towell  for his wonderful blog here.

Disclaimer: As already stated, all these are based on my experiences and may have some gaps which I would love to learn from feedback and your experiences.

Tip # 1. Frequently use sorted tables within table expression as it triggers an implicit Binary Search since we don’t have any provision to specify ‘BINARY SEARCH‘ clause in table expression.

DATA :  lt_mseg  TYPE SORTED TABLE OF mseg 
        WITH NON-UNIQUE KEY grund.

DATA : ls_mseg TYPE mseg.

" Below will trigger implicit Binary Search
ls_mseg = lt_mseg[ grund = '<Some value>' ].

Tip # 2.  Use of Value operator only works with Data types accessible in current scope.

Sandra Rossi : Thank you for correcting me.

" Class 1 - Method 1
DATA : ls_val TYPE bwart_range.

" ts_val - Public type in Class 1
ls_val = VALUE ts_val( low = 'ABC' ).

" Class 2 - Method 1
DATA : ls_val TYPE bwart_range.

" ts_val - Public type in Class 1
ls_val = VALUE Class1=>ts_val( low = 'ABC' ).

" --------------------------------------------------------

" Class 1 - Method 1
DATA : ls_val TYPE bwart_range.

" ts_val - Private type in Class 1
ls_val = VALUE ts_val( low = 'ABC' ).

" Class 2 - Method 1
DATA : ls_val TYPE bwart_range.

" ts_val - Private type in Class 1 so gives Syntax Error
ls_val = VALUE Class1=>ts_val( low = 'ABC' ).

Tip # 3. Define sorted tables carefully. There is difference between both syntaxes –

a. Data: <Itab>  TYPE SORTED TABLE OF < > with <Key Attributes> <Field 1> , <Field 2 >.

b.  Data: <Itab>  TYPE SORTED TABLE OF < > with <Key Attributes> <Field 1>  <Field 2 >. ( Generally we use this one )

Matthew Billingham Thank you for giving a good example.

DATA : lt_po_detail_sort TYPE SORTED TABLE OF ekpo 
                         WITH NON-UNIQUE KEY ebeln, ebelp.

" Same as
DATA : lt_po_detail_sort TYPE SORTED TABLE OF ekpo
                         WITH NON-UNIQUE KEY ebeln.
DATA ebelp. " Declares a single character variable

Tip # 4. < Use the Corresponding operator as below

<Structure1 – Data type 1 > = CORRESPONDING <Data type 1> ( BASE  (  < Structure 2 – Data type 1 > )  < Structure 3 – Data type 2 > )

DATA:  ls_mara_proc  TYPE zmara,
       ls_mara       TYPE zmara,
       ls_admin_data TYPE zs_admindata.

    " Combine the custom material header 
    " fields and admin data
    " Point to note is component fields in
    " structure zs_admindata are also in zmara
    ls_mara_proc = CORRESPONDING 
                   zmara( BASE ( ls_mara )  ls_admin_data  ).

Tip # 5. We can use Table Expression within For Loop as well. Something like

<Itab 1> = Value <Table Type>( FOR <Work Area> IN < Itab 2 with data>  ( <field1> = <Itab 3> [ < search clause > ]-<field 1>

<field2> = < Work Area>-<field 2> )  )

DATA: lt_quality    TYPE ztt_quality,
      lt_quality_db TYPE ztt_quality,
      lt_mat_plant  TYPE SORTED TABLE OF zs_mat_plant 
                         WITH NON-UNIQUE KEY matnr.

" Map the selected materials and plants
lt_quality = VALUE ztt_quality(
             FOR ls_quality
             IN  lt_quality_db 
             ( matnr  = ls_quality-matnr
               werks  = lt_mat_plant[ matnr = ls_quality-matnr ]-werks ) ).

Tip # 6.  We can use Corresponding With Base, Mapping, Except and with Value operator. It is very handy when we need to combine data from multiple structures in a single structure.

Examples from standard documentation.

Tip # 7. With Assign statement in Table expression where use field symbol, we need not check the exception cx_sy_itab_line_not_found instead we should check the value of sy-subrc which is set to indicate read failure.

Tip # 8. We can directly unassign field symbols without checking if they are assigned but we cannot directly clear field symbols without checking if they are assigned i.e.

UNASSIGN < Field symbol > –  Works

CLEAR < Field symbol > – Does not work (dumps if field symbol is not assigned)

Tip # 9. Whenever we have situations to apply control breaks etc. we should go for

‘Group By‘ clause instead. It’s more readable , easy to maintain and does not come with

hassle of fields getting asteriked. Also, it does not cause quadrtic loops.

 LOOP AT ct_all_mat ASSIGNING FIELD-SYMBOL(<fs_all_mat>)
           GROUP BY ( field1 = <fs_all_mat>-field1 )
           ASCENDING ASSIGNING FIELD-SYMBOL(<fs_all_mat_grp_tab>).

      " Prepare the sequence number as a running number
      " irrespective of field1
      LOOP AT GROUP <fs_all_mat_grp_tab> 
              ASSIGNING FIELD-SYMBOL(<fs_all_mat_grp_rec>).
       " Processing for all item in a Group
      ENDLOOP.
" Processing once for each matching group.

 ENDLOOP.

I will keep adding as I learn.