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Predefined ABAP Types Locate the document in its SAP Library structure

These data types are predefined in the SAP Web AS ABAP kernel, and are visible in all ABAP programs. You can use predefined types to define local data types and objects in a program and to specify the type of interface parameters and field symbols.

Predefined Elementary ABAP Types with Fixed Length

These predefined elementary data types are used to specify the types of individual fields whose lengths are always fixed at runtime. The following table shows the different fixed-length data types. All field lengths are specified in bytes.

Data Type

 

Initial Field Length

Valid Field Length

Initial Value

 

Meaning

 

Numeric Types

I

4

4

0

Integer (whole number)

F

8

8

0

Floating point number

P

8

1 - 16

0

Packed number

Character types

C

1

1 - 65535

'  '

Text Field

(alphanumeric characters)

D

8

8

'00000000'

Date field

(Format: YYYYMMDD)

N

1

1 - 65535

'0 … 0'

Numeric text field

(numeric characters)

T

6

6

'000000'

Time field

(format: HHMMSS)

Hexadecimal type

X

1

1 - 65535

X'0 … 0'

Hexadecimal field

Data types D, F, I, and T describe the technical attributes of a data object fully. Data types C, N, P, and X are generic. When you use a generic type to define a local data type in a program or a data object, you must specify the field length and, in the case of type P, the number of decimal places. When you user generic types to specify the types of interface parameters of field symbols, you do not have to specify the technical attributes.

The initial value (and initial field length in the case of the generic types), are values that are used implicitly in short forms of the TYPES and DATA statements.

The fixed-length predefined types are divided into:

Numeric Types

You can use type I data for counters, numbers of items, indexes, time periods, and so on.

You can use type P data for such values as distances, weights, amounts of money, and so on.

You use type F fields when you need to cope with very large value ranges and rounding errors are not critical.

Using I and F fields for calculations is quicker than using P fields. Arithmetic operations using I and F fields are very similar to the actual machine code operations, while P fields require more support from the software. Nevertheless, you have to use type P data to meet accuracy or value range requirements.

Character types

Of the five non-numeric types, the four types C, D, N, and T are character types. Fields with these types are known as character fields. Each position in one of these fields takes up enough space for the code of one character. Currently, ABAP only works with single-byte codes such as ASCII and EBCDI.

As of Release 6.10, Web Application Server supports both unicode and non-unicode systems. Non-unicode systems are conventional SAP systems in which a character is generally represented by a byte. Unicode systems are SAP systems that are based on a unicode character display and are supported by an appropriate operating system and database.

 

Hexadecimal Type

The remaining non-numeric type - X - always interprets individual bytes in memory. One byte is represented by a two-digit hexadecimal display. The fields with this type are called hexadecimal fields. In hexadecimal fields, you can process single bits.

Predefined Elementary ABAP Types with Variable Length

These predefined elementary data types are used to specify the types of individual fields whose lengths are not fixed until runtime.  There are two predefined ABAP data types with variable length that are generically known as strings:

        STRING for character strings

A string is a sequence of characters with variable length. A string can contain any number of alphanumeric characters. The length of a string is the number of characters multiplied by the length required for the internal representation of a single character.

        XSTRING for byte strings

A byte string is a hexadecimal type with variable length. It can contain any number of bytes. The length of a byte string is the same as the number of bytes.

When you create a string as a data object, only a string header is created statically. This contains administrative information. The actual data objects are created and modified dynamically at runtime by operational statements.

The initial value of a string is the empty string with length 0. A structure that contains a string is handled like a deep structure. This means that there are no conversion rules for structures that contain strings.

Predefined Complex Data Types

ABAP contains no predefined complex data types that you can use to define local data types or data objects in a program. All complex data types are based on elementary ABAP types, and are constructed in ABAP programs or in the ABAP Dictionary.

 

 

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