Editing ABAP (section)

==Internal tables in ABAP==
Internal tables are an important feature of the ABAP language. An internal table is defined similarly to a vector of ''struct''s in C++ or a vector of objects in Java. The main difference with these languages is that ABAP provides a collection of statements to easily access and manipulate the contents of internal tables. Note that ABAP does not support arrays; the only way to define a multi-element data object is to use an internal table.<ref>{{cite web |last= |first= |date= |title=Internal Tables |url=https://help.sap.com/doc/saphelp_nw73ehp1/7.31.19/en-US/fc/eb35de358411d1829f0000e829fbfe/content.htm?no_cache=true |website= |location= |publisher=SAP |access-date=}}</ref>

Internal tables are a way to store variable data sets of a fixed structure in the working memory of ABAP, and provides the functionality of dynamic arrays. The data is stored on a row-by-row basis, where each row has the same structure.

Internal tables are preferably used to store and format the content of database tables from within a program. Furthermore, internal tables in connection with structures are an important means of defining complex data structures in an ABAP program.

The following example defines an internal table with two fields with the format of database table VBRK.

<syntaxhighlight lang="abap">
* First define structured type
TYPES: BEGIN OF t_vbrk,
         VBELN TYPE VBRK-VBELN,
         ZUONR TYPE VBRK-ZUONR,
       END OF t_vbrk.

* Now define internal table of our defined type t_vbrk
DATA : gt_vbrk TYPE STANDARD TABLE OF t_vbrk,
       gt_vbrk_2 TYPE STANDARD TABLE OF t_vbrk.   "easy to define more tables

* If needed, define structure (line of internal table)
* Definition with type or with reference to internal table:
DATA : gs_vbrk TYPE t_vbrk,
       gs_vbrk_2 LIKE LINE OF gt_vbrk_2.

* You can also define table type if needed
TYPES tt_vbrk TYPE STANDARD TABLE OF t_vbrk. 
</syntaxhighlight>