ABAP 740 – FOR Iteration Expression

As of ABAP 740, there is a new iteration expression available – FOR. This can be used along with VALUE to populate the desired data. Lets see how it works.

Introduction

ABAP 740 has lot of new features and FOR is one of them. FOR is the Iteration Expression. An iteration expression is to perform the iteration on the table. The FOR can be used with Constructor Operators – like NEW, VALUE. It is like the LOOP but using the different pattern.

I have already used the FOR in the ABAP 740 – Mesh Path – Forward and Inverse Association articles, you must have known it by now 🙂

Syntax

At simple level, the syntax is like this:

DATA(t_city) =
  VALUE tt_citys(
    FOR ls_cust IN t_customres
      INDEX INTO cust_index
    ( ls_cust-city )
  ).

Point to note:

You need to specify the work area of the field symbol. The type of the work area is determined with the type of the internal table. These are only visible within the FOR expression. They can’t be used outside of the FOR.
The INDEX specification will assign the index of the table in current row
You can specify the where condition. This is pretty much same as what you do for LOOP.
You can also specify the LET expression. This is a new expression which you can use for specifying some values for few of the components. This can be the calculation or simple default value.

Example 1 – Append value of 1 field into another table using FOR

In this simple use of FOR, single column table is populated using FOR and VALUE.

TYPES:
  BEGIN OF ty_customer,
    customer TYPE char10,
    name     TYPE char30,
    city     TYPE char30,
    route    TYPE char10,
  END   OF ty_customer.
TYPES: tt_customers TYPE SORTED TABLE OF ty_customer
          WITH UNIQUE KEY customer.
 
TYPES: tt_citys TYPE STANDARD TABLE OF char30 WITH EMPTY KEY.
 
DATA(t_customres) =
  VALUE tt_customers(
    ( customer = 'C0001' name = 'Test Customer 1' city = 'NY' route = 'R0001' )
    ( customer = 'C0002' name = 'Customer 2'      city = 'LA' route = 'R0003' )
    ( customer = 'C0003' name = 'Good Customer 3' city = 'DFW' route = 'R0001' )
    ( customer = 'C0004' name = 'Best Customer 4' city = 'CH' route = 'R0003' )
  ).
 
* FOR to get the column CITY
DATA(t_city) =
  VALUE tt_citys(
    FOR ls_cust IN t_customres
    ( ls_cust-city )
  ).

As you see, the debugger shows that values are actually moved from the T_CUSTOMERS to T_CITY.

Example 2 – FOR with WHERE condition

Here Moving the field CITY from T_CUSTOMERS to T_CITY_IN_03 only where ROUTE is some specific value

DATA(t_city_in_03) =
  VALUE tt_citys(
    FOR ls_cust IN t_customres WHERE ( route = 'R0001' )
    ( ls_cust-city )
  ).

Same, debugger shows the values in the T_CITY_IN_03:

Also NOTE that LS_CUST is declared in both examples. There is any syntax error here as the visibility is only within the specific FOR.

Example 3 – Nested FOR with 2 tables

Here Added few more table in the bunch. The FOR is a nested where the 2nd FOR has the WHERE condition to only loop where the value is same. FOR can be used with multiple nested loops. This is same as Nested LOOPs using the LOOP AT and LOOP AT WHERE.

TYPES:
  BEGIN OF ty_route_config,
    route   TYPE char10,
    c_type  TYPE char10,
    c_value TYPE char40,
  END   OF ty_route_config.
TYPES: tt_route_config TYPE SORTED TABLE OF ty_route_config
          WITH UNIQUE KEY route c_type.
 
TYPES:
  BEGIN OF ty_routes,
    route TYPE char10,
    name  TYPE char40,
  END   OF ty_routes.
TYPES: tt_routes TYPE SORTED TABLE OF ty_routes
        WITH UNIQUE KEY route.
 
DATA(t_routes) =
  VALUE tt_routes(
    ( route = 'R0001' name = 'Route 1' )
    ( route = 'R0002' name = 'Route 2' )
    ( route = 'R0003' name = 'Route 3' )
  ).
 
DATA(t_rc) =
  VALUE tt_route_config(
    ( route = 'R0001' c_type = 'RTYPE' c_value = 'DSD' )
    ( route = 'R0001' c_type = 'MAX'   c_value = '10'  )
    ( route = 'R0002' c_type = 'RTYPE' c_value = 'WH' )
    ( route = 'R0002' c_type = 'MAX'   c_value = '100'  )
    ( route = 'R0003' c_type = 'RTYPE' c_value = 'WH' )
    ( route = 'R0004' c_type = 'RTYPE' c_value = 'DSD' )
  ).
 
 
* Nested FOR - 2 levels
TYPES: tt_names TYPE STANDARD TABLE OF char40 WITH DEFAULT KEY.
DATA(t_route_names) =
  VALUE tt_names(
    FOR ls_cust_1 IN t_customres
    FOR ls_route  IN t_routes WHERE ( route = ls_cust_1-route )
    ( ls_route-name )
  ).

In debugger, you can see the final table has name of the route.

Example 4 – Nested LOOP with multiple tables

Same as example 3, but one more table in the FOR

* Nested FOR - 3 levels
TYPES:
  BEGIN OF ty_routes_max,
    route   TYPE char10,
    name    TYPE char40,
    c_value TYPE char40,
  END   OF ty_routes_max.
TYPES: tt_routes_max TYPE STANDARD TABLE OF ty_routes_max
        WITH DEFAULT KEY.
 
DATA(t_routes_max) =
  VALUE tt_routes_max(
    FOR ls_cust_2   IN t_customres
    FOR ls_route_2  IN t_routes WHERE ( route = ls_cust_2-route )
    FOR ls_rc_2     IN t_rc     WHERE ( route = ls_route_2-route
                                   AND  c_type = 'MAX' )
    ( route = ls_route_2-route
      name  = ls_route_2-name
      c_value = ls_rc_2-c_value )
  ).

In the debugger, you can see the result table has only routes with MAX config.

Example 5 – LET with specific (and default) value with FOR

Here you can see the FOR is used with LET. The LV_NAME is read using the tabular expression or [ ] from the table. The LV_ROUE is also read using the tabular expression but for only first row [1].

TYPES:
  BEGIN OF ty_routes_cust,
    route    TYPE char10,
    name     TYPE char40,
    customer TYPE char10,
  END   OF ty_routes_cust.
TYPES: tt_routes_cust TYPE STANDARD TABLE OF ty_routes_cust
        WITH DEFAULT KEY.
 
*data(t_routes_cust) =
*  value tt_routes_cust(
*    for ls_cust_l   in t_customres
*      "where ( customer = 'C0001' )
*      let  LV_NAME   =  'teSTING name'
*           LV_ROUTE  =  'TESTING ROUTE'
*           IN NAME = LV_NAME
*              ROUTE = LV_ROUTE
*    ( CUSTOMER = ls_cust_L-CUSTOMER )
*  ).
 
 
DATA(t_routes_cust) =
  VALUE tt_routes_cust(
    FOR ls_cust_l   IN t_customres
      INDEX INTO cust_index
      "where ( customer = 'C0001' )
      LET  lv_name   =  t_routes[ route = t_customres[ cust_index ]-route ]-name
           lv_route  =  t_routes[ 1 ]-route
           IN name = lv_name
              route = lv_route
    ( customer = ls_cust_l-customer )
  ).

Debugger is like this for this example:

Example 6 – FOR with LET to populate the RANGE

This is cool. You can use the FOR with LET to specify the default value and fill up the range. Awesome!

TYPES: tt_route_range TYPE RANGE OF char10.
 
DATA(t_route_range) =
  VALUE tt_route_range(
    "( sign = 'I' option = 'BT' low = '001' high = '002' )
    FOR ls_cust_r IN t_customres
      LET s = 'I'
          o = 'EQ'
        IN sign     = s
           option   = o
    ( low = ls_cust_r-route )
  ).

Note that range is populated with the fixed I and EQ.

For with GROUP –

There are more into the FOR. You can specify the GROUP to only obtain the unique rows. I don’t have system with this yet so, explore 🙂 – ABAP 740 – FOR at ABAP Help

Table of Content – ABAP 740 Concepts

Rajeev

# July 1st, 2015 at 10:12 am

Really very nice and clear explanation..
Best site to stay up to date with latest ABAP changes !! 🙂

Gokul

# July 3rd, 2015 at 1:47 am

this is super and good.

I have one question, in the table and workarea comes as inline declaration.
how we will use it if the table is declaration or if i am using the existing structure or custom one

Naimesh Patel

# July 6th, 2015 at 1:09 pm

@Gokul,

The inline declaration is smart and knows which structure is being return back based on the type. So, this would declare T_ROUTE_MAX with type TT_ROUTE_MAX

 
DATA(t_routes_max) =
  VALUE tt_routes_max(

Thanks,
Naimesh Patel

TashTash

# August 11th, 2015 at 7:33 am

There is any why to use the FOR command and get not doplicated values?

# August 12th, 2015 at 8:38 am

@TashTash – I haven’t tried but it should be possible with the GROUP BY addition for the FOR. I would give a try and see if it gives Unique values.

Welcome !

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