ABAP Keyword Documentation → ABAP - Reference → Declarative statemnts → Data Types and Data Objects → Declaring Data Types → TYPES
TYPES - TABLE OF
Other versions: 7.31 | 7.40 | 7.54
Syntax
TYPES dtype { {TYPE tabkind OF [REF TO] type}
| {LIKE tabkind OF dobj} }
[tabkeys]
[INITIAL SIZE n].
Addition
Effect
This statement defines a table type dtype
with a specific row type, a table category tabkind
, and table keys tabkeys
.
The row type is determined by entering the data type type
after TYPE
and data type dobj
after LIKE
:
-
type
can be a non-generic data type from ABAP Dictionary, a non-generic public data type of a public data type or global class, a non-generic data type local to a program, or any ABAP type from the table of predefined ABAP types. The generic ABAP typesc
,n
,p
, andx
are implicitly extended to the standard length without decimal places from the table of predefined ABAP types.
If the additionREF TO
is specified beforetype
ordobj
, then the row type is a reference type. The information specified in section reference types can then be entered fortype
anddobj
. -
The same applies to
dobj
as toTYPES ... LIKE
.
Addition
... INITIAL SIZE n
Effect
The optional addition INITIAL SIZE
has two meanings:
-
Note for the internal memory management of internal tables
Internal tables are stored in the memory block by block. After the optional addition INITIAL SIZE, you can specify a number of rowsn
directly as a positive number without sign or as a numeric constant to notify the system of the size of the initial block in the memory (reserved by the system for an internal table of the table type). By default, and ifn
is specified as 0, the system allocates a suitable initial memory area automatically.
If the initial memory area is not large enough, further blocks are created using a duplicate strategy until a maximum size is reached. After this, all blocks are created with a constant size between eight and 16 KB.
If the value ofn
causes the initial blocks to become too big, the size of the initial memory area is also defined by the system. -
Size of Rankings
To create a ranking in the internal table using theSORTED BY
addition to the APPEND statement, specify a value greater than 0 afterINITIAL SIZE
and this determines the size of the ranking.
Programming Guideline
Modify the initial memory requirements only for nested tables
Notes
- You are advised to specify the initial memory requirements only when the number of entries in the table has already been specified and the initial main memory requirement has an adequate value. This can be especially important for internal tables that are components of table types and only contain a few rows.
-
Instead of
APPEND SORTED BY
, the statementSORT
must be used so that theINITIAL SIZE
addition is no longer required here.
Example
Defines a non-generic sorted table type. The row type corresponds to the structure of the database table SPFLI. Two key fields are defined for the primary table key.
TYPES spfli_sort TYPE SORTED TABLE OF spfli
WITH UNIQUE KEY carrid connid.