Data Types and Variable Declaration

ABAP has the types a business system needs. That amounts and quantities have a type designed for exact decimal arithmetic says a lot about the language.

Built-in types

The main built-in types

Type	Content	Default length	Initial value
C	Fixed-length text	1	Space
N	Numeric text, zero padded	1	'0'
D	Date, YYYYMMDD	8	'00000000'
T	Time, HHMMSS	6	'000000'
I	Integer, 4 bytes	—	0
INT8	Integer, 8 bytes	—	0
P	Packed decimal	8	0
F	Floating point	8	0
STRING	Variable-length text	Variable	Empty
XSTRING	Variable-length bytes	Variable	Empty

N compared with C

How they differ

DATA lv_num TYPE n LENGTH 5.
DATA lv_chr TYPE c LENGTH 5.

lv_num = 42.       " gives '00042' — zero padded
lv_chr = 42.       " gives '42   ' — space padded

Document numbers and material codes in SAP are usually N fields, which is why they display with leading zeros.

Declaring variables

Declarations

" Built-in type directly
DATA lv_name TYPE c LENGTH 30.
DATA lv_amount TYPE p LENGTH 8 DECIMALS 2.

" Referencing a Data Dictionary type (preferred)
DATA lv_matnr TYPE matnr.

" Referencing a table field
DATA lv_bukrs TYPE bkpf-bukrs.

" With an initial value
DATA lv_count TYPE i VALUE 10.

" Constant
CONSTANTS lc_status TYPE c LENGTH 1 VALUE 'A'.

Structures

Defining and using a structure

TYPES: BEGIN OF ty_item,
         matnr TYPE matnr,
         maktx TYPE maktx,
         menge TYPE i,
       END OF ty_item.

DATA ls_item TYPE ty_item.
ls_item-matnr = 'MAT-001'.

" A Dictionary structure
DATA ls_mara TYPE mara.

Internal table types

Declaring internal tables

DATA lt_items TYPE STANDARD TABLE OF ty_item.
DATA lt_mara  TYPE STANDARD TABLE OF mara.

DATA lt_sorted TYPE SORTED TABLE OF ty_item
               WITH UNIQUE KEY matnr.

Inline declarations

From ABAP 7.4

SELECT SINGLE * FROM mara INTO @DATA(ls_mara) WHERE matnr = @lv_matnr.

LOOP AT lt_items INTO DATA(ls_item).
  WRITE: / ls_item-matnr.
ENDLOOP.

DATA(lt_numbers) = VALUE int_tab( ( 1 ) ( 2 ) ( 3 ) ).

Declaring at the point of use keeps declarations near the logic that needs them and narrows variable scope, which makes code easier to read.

📖 Unfamiliar term? Look it up in the SAP glossary.