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ABAP Keyword Documentation →  ABAP - Reference →  Declarative statemnts →  Data Types and Data Objects →  Declaring Data Types →  TYPES →  TYPES - BEGIN OF 


Short Reference

Other versions: 7.31 | 7.40 | 7.54


TYPES comp TYPE struc_type BOXED. 


This statement defines a substructure comp of a structure as a static box. It can only be used within the relevant structure definition with the BEGIN OF and END OF additions of the TYPES statement and must be at the highest component level and not within nested BEGIN OF ... END OF blocks.

A structured data type must be specified for struc_type. This can be a local program structured type, a visible structured type of a class or a global interface, or a structure from the ABAP Dictionary, and can contain static boxes.

Static boxes support initial value sharing. The structure is not saved in the higher-level context itself. Instead, an internal reference that points to the actual structure is stored in place of the component. A static box is therefore a deep component.


  • A structure with a static box is a deep structure and the corresponding restrictions apply.
  • The BOXED addition defines the static box with reference to its context (structure or class). A data type that is declared by a direct TYPE or LIKE reference to a static box is assigned its data type but is not a static box.
  • When a static box is copied from one structure to another structure using the INCLUDE TYPE|STRUCTURE statement, its static box attribute is also copied.
  • If you want to create a nested structure whose static boxes already contain static boxes, this is only possible if each substructure affected exists as an independent type. You cannot specify BOXED for substructures that exist as a result of nested TYPES BEGIN OF ... TYPES END OF.
  • The BOXED addition can also be used in the DATA statement to declare a structured attribute of a class or an interface.


The following section shows the permitted use of the addition BOXED with the statement TYPES. In a structured type t_struc2, a substructure t_struc2-comp2 of type t_struc1 is declared as a static box.

TYPES: BEGIN OF t_struc1, 
         comp1 TYPE c LENGTH 100, 
         comp2 TYPE n LENGTH 100, 
       END OF t_struc1. 

TYPES: BEGIN OF t_struc2, 
         comp1 TYPE string, 
         comp2 TYPE t_struc1 BOXED, 
       END OF t_struc2.