topic Loop Statement in Application Development and Automation Discussions

Loop Statement

Anindya — Fri, 07 Dec 2007 08:49:52 GMT

Hi All,

LOOP AT idoc_data FROM tab_index.

Here idoc_data is a structure and not a table and tab_index holds a numeric value.

How does this statement work?

Thanks in advance

Anindya

Message was edited by:

anindya mukhopadhyay

Re: Loop Statement

Former Member — Fri, 07 Dec 2007 08:55:48 GMT

It means the system'll start to loop the table from record number <b>tab_index</b>.

For example the table ITAB has 100 records, but I need to read the data only from 75th record:

LOOP AT ITAB FROM 75

These code is similar to this:

TAB_INDEX = 75.
DO.
  READ TABLE ITAB INDEX TAB_INDEX.
  IF SY-SUBRC <> 0. EXIT. ENDIF.
  TAB_INDEX = TABX_INDEX + 1.
ENDDO.

If I wants to read the record from 75th to 90th

LOOP AT ITAB FROM 75
               TO 90.

These code is similar to this:

AB_INDEX = 75.
DO.
  READ TABLE ITAB INDEX TAB_INDEX.
  IF SY-SUBRC <> 0. EXIT. ENDIF.
  TAB_INDEX = TABX_INDEX + 1.
  
  if TAB_INDEX > 90. EXIT. ENDIF.
ENDDO.

So you should check how the index TAB_INDEX is calculated.

Max

Re: Loop Statement

Former Member — Fri, 07 Dec 2007 09:00:34 GMT

Loop at itab from index l_index.

endloop.

this will start from the i_index th record and process further u can also use TO option to limit the looping.

But this will have no effect on a structure . it s used only along with itab

Re: Loop Statement

Anindya — Fri, 07 Dec 2007 10:02:13 GMT

Hi,

I got some valuable insights from the answers that has been posted and Thanks to you guys for your answers.

But the fundamantal Question remains why a strusture has been used here.

Re: Loop Statement

Former Member — Fri, 07 Dec 2007 10:43:55 GMT

The data IDOC_DATA has to be an internal table otherwise the stament <b>LOOP AT idoc_data FROM tab_index</b> wouldn't make a sense and the system'd generate a syntax error.

We can't know how the data IDOC_DATA is defined and why it's used: you should past the code.

I can only suppose it needs to read the data of idoc segments.

Max

Re: Loop Statement

former_member199581 — Fri, 07 Dec 2007 10:48:30 GMT

If structure IDOC_DATA your are talking about it's the same that it's defined in DDIC, then this is a table type with a line type of structure EDIDD.

So the LOOP statement makes sense here.

Otherwise, the only structure where you can put a LOOP on is the special structure SCREEN, and that's not this case.

If I declare this:

DATA struc TYPE idoc_data.

Then struc become a table and not a structured field.

Hope this helps,

Roby.