ABAP/4 ОКМ ДМ экономическая информатика 4GL Теория и практика обработки информации

Компьютерный язык ABAP/4 - ключевые слова

TYPES

Variants

1. TYPES typ.
2. TYPES typ(len).
3. TYPES: BEGIN OF rectyp,
...
END OF rectyp.

Effect

The TYPES statement introduces user-defined data types . As with standard data types, you can use them when creating data objects and when assigning types to formal parameters and field symbols. User-defined data types are an essential component of the ABAP/4 type concept .

Variant 1

TYPES f.

Additions

1. ... TYPE typ1
2. ... LIKE f
3. ... TYPE typ1 OCCURS n
4. ... LIKE f OCCURS n
5. ... TYPE LINE OF itabtyp
6. ... LIKE LINE OF itab
7. ... DECIMALS n

Effect

Creates a new type. If the TYPE addition is not used, the new type points to the standard type C .

The type name typ can be up to 30 characters long. Apart from the special characters '(', ')', '+', '.', ',', ':', '-', '<' and '>', you can use any characters. Numbers are allowed, but the name cannot consist of numbers alone.

Recommendations for type names:
Always use a letter as the first character.
Use the underscore as the link in multiple word names (e.g. NEW_PRODUCT ).

Addition 1

... TYPE typ1

Effect

Defines the new type with the type typ1 . typ1 can be one of the predefined types specified below or a type you define yourself with TYPES .
The length (SL) of the type typ is the same as the type typ1 .

Type Description Std len. Initial value

C Text (character) 1 Blank
N Numeric text 1 '00...0'
D Date (YYYYMMDD) 8 '00000000'
T Time (HHMMSS) 6 '000000'
X Hexadecimal 1 X'00'
I Whole number (integer) 4 0
P Packed number 8 0
F Floating point number 8 '0.0'

Example


TYPES NUMBER TYPE I.

This defines the type NUMBER NUMBER with the type I . It can then be used in the program.

Notes

The data type I is the whole number type for the hardware you are using. Its value range is -2**31 to 2**31-1 (-2.147.483.648 to 2.147.483.647).
While type P is used for money amount fields, you should use type I for number fields, index fields, position specifications, etc.
Apart from zero, type F allows you to display positive and negative numbers in the range from 1E-307 to 1E+307 with 15 decimal places. (The ABAP/4 processor uses the floating point operations of the relevant hardware and does not attempt to standardize them.) Floating point literals must be enclosed in quotation marks. The standard output length is 22.
Input in type F fields can be formatted differently:

Decimal number with or without sign, with or without decimal point.
In the form E, where the mantissa is a decimal number and the exponent can be specified with or without a sign. (Examples of floating point literals: '1', '-12.34567', '-765E-04', '1234E5', '+12E+34', '+12.3E-4', '1E160').

Floating point arithmetic is fast on our hardware platforms. It is ideal when you require a large value range and can take rounding errors into account when making calculations. Such rounding errors can occur when converting from external (decimal) format to internal format (base 2 or 16) or vice-versa (see ABAP/4 number types ).

Addition 2

... LIKE f

Effect

Defines the type typ with the type of the field f . f may be a database field or an already defined internal field.

Example


TYPES TABLE_INDEX_TYP LIKE SY-TABIX.

The type TABLE_INDEX_TYP now points to the type of the field SY-TABIX (index for internal tables).

Note

This addition is useful in a number of cases, since any field type changes are automatically known to the program. Also, any unnecessary and unwanted conversions are not performed.

Addition 3

... TYPE typ1 OCCURS n

Effect

Defines the type of an internal table without a header line. An internal table without a header line consists of any number of table lines that have the same structure as that specified by TYPE .
You fill and process an internal table with statements such as APPEND , READ TABLE , LOOP and SORT .
The OCCURS parameter n specifies how many table lines of storage is required. This storage reservation process does not happen until the first line is inserted in the table. The value n of the OCCURS specification has no effect on type checking, i.e. data objects which have types with different OCCURS specifications are type-compatible.

Example

TYPES: TAB_TYPE TYPE I OCCURS 20.
DATA: TAB TYPE TAB_TYPE,
TAB_WA TYPE I.

TAB_WA = 1.
APPEND TAB_WA TO TAB.
TAB_WA = 2.
APPEND TAB_WA TO TAB.
The internal table TAB now consists of two table entries.

Addition 4

... LIKE f OCCURS n

Effect

Defines the type of an internal table without a header line. This table consists of any number of table lines which have the structure specified by the data object f . Processing is the same as for addition 3.

Example


DATA:  BEGIN OF PERSON,
         NAME(20),
         AGE TYPE I,
       END OF PERSON.
TYPES  TYPE_PERSONS LIKE PERSON OCCURS 20.
DATA   PERSONS TYPE TYPE_PERSONS.

PERSON-NAME = 'Michael'.
PERSON-AGE  = 25.
APPEND PERSON TO PERSONS.
PERSON-NAME = 'Gabriela'.
PERSON-AGE  = 22.
APPEND PERSON TO PERSONS.

The internal table PERSONS now consists of two table entries.

Addition 5

... TYPE LINE OF itabtyp

Effect

The specified type itabtyp must be the type of an internal table with or without a header line. The statement creates a type corresponding to the line type of the specified table type.

Example


TYPES TAB_TYP TYPE I OCCURS 10.
TYPES MY_TYPE TYPE LINE OF TAB_TYP.

The type MY_TYPE now has the same attributes as a line of the table type TAB_TYP and is thus type I .

Addition 6

... LIKE LINE OF itab

Effect

The data object itab must be an internal table with or without a header line. The statement defines a type which corresponds to the line type of the specified table.

Example


DATA  TAB TYPE I OCCURS 10.
TYPES MY_TYPE LIKE LINE OF TAB.

The type MY_TYPE now has the same attributes as the line type of the table TAB and thus has the type I .

Addition 7

... DECIMALS n

Effect

This addition only makes sense with the field type P . When making calculations and outputting data, a field of this type has n decimal places. n must be a value between 0 and 14.

Normally, the attribute for fixed point arithmetic is set with newly created programms. If you switch this attribute off, the DECIMALS -specification is taken into account on output, but not when making calculations. In this case, the programmer must take care that the decimal point is in the right place by multiplying or dividing (COMPUTE ) by the appropriate power of ten.
When making calculations, you should always have fixed point arithmetic switched on. Then, even intermediate results (division!) are calculated with the greatest possible accuracy (31 decimal places).
To decide whether the fixed point type P or the floating point type F is more suitable, see also "ABAP/4 number types ".

Variant 2

TYPES typ(len).

Additions

Similar to variant 1

Effect

Creates the type typ with the length len .
This variant should only be used with the types C , N , P and X . Other types can only be created in the standard length (see table under effect of variant 1).
The permitted lengths depend on the type being pointed to:

Type Permitted lengths

C 1 - 65535
N 1 - 65535
P 1 - 16
X 1 - 65535

Note

For each byte, you can display one character, two decimal digits or two hexadecimal digits. With P fields, one place is reserved for the leading sign, so that a P field of the length 3 can contain 5 digits, while an X field of the length 3 can contain 6 digits. Both have an output length of 6.

Variant 3

TYPES: BEGIN OF rectyp,
...
END OF rectyp.

Effect

Defines the field string type rectyp by grouping together all fields of the type rectyp defined between " BEGIN OF rectyp " and " END OF rectyp ". Each name is prefixed by " rectyp- ".

Example


TYPES: BEGIN OF PERSON,
         NAME(20) TYPE C,
         AGE      TYPE I,
       END   OF PERSON.

ABAP/4 ОКМ ДМ экономическая информатика 4GL Теория и практика обработки информации

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