5.3.16.1 Computational Items
A computational item is a value used in arithmetic operations. It must be
numeric. If the USAGE of a group item is described with any of these
items, the elementary items within the group have this usage.
The maximum length of a computational item is 18 decimal digits.
The PICTURE of a computational item can contain only:
- 9
- One or more numeric character positions
- S
- One operational sign
- V
- One implied decimal point
- P
- One or more decimal scaling positions
X COMPUTATIONAL-1 and COMPUTATIONAL-2 items (internal floating-point) cannot
X have PICTURE strings.
-
BINARY
-
Specified for binary data items. Such items have a decimal equivalent
consisting of the decimal digits 0 through 9, plus a sign. Negative
numbers are represented as the two's complement of the positive number
with the same absolute value.
The amount of storage occupied by a binary item depends on the number
of decimal digits defined in its PICTURE clause:
|
|
Digits in PICTURE Clause |
Storage Occupied |
1 through 4 |
2 bytes (halfword) |
5 through 9 |
4 bytes (fullword) |
10 through 18 |
8 bytes (doubleword) |
The operational sign for "big-endian" binary data (such as OS/390 and
VM) is contained in the left most bit of the binary data. The
operational sign for "little-endian" binary data is contained in the
left most bit of the right most byte of the binary data.
X Note: BINARY, COMPUTATIONAL, and COMPUTATIONAL-4 data items can be
X affected by the BINARY and TRUNC compiler option specifications. For
X information on the effect of these compiler options, see the IBM COBOL
X Programming Guide for your platform. (The BINARY compiler option is
X only applicable to OS/2 and Windows programs.)
-
PACKED-DECIMAL
-
Specified for internal decimal items. Such an item appears in storage
in packed decimal format. There are 2 digits for each character
position, except for the trailing character position, which is
occupied by the low-order digit and the sign. Such an item can
contain any of the digits 0 through 9, plus a sign, representing a
value not exceeding 18 decimal digits.
The sign representation uses the same bit configuration as the 4-bit
sign representation in zoned decimal fields. For details, see the IBM
COBOL Programming Guide for your platform.
-
COMPUTATIONAL or COMP (Binary)
-
This is the equivalent of BINARY. The COMPUTATIONAL phrase is
synonymous with BINARY.
-
X COMPUTATIONAL-1 or COMP-1 (Floating-Point)
-
X Specified for internal floating-point items (single precision).
X COMP-1 items are 4 bytes long.
X >_Workstation_> COMP-1 data items are affected by the
X FLOAT(NATIVE|HEX) compiler option. For details, see the IBM COBOL
X Programming Guide for your platform <_Workstation_<
-
X COMPUTATIONAL-2 or COMP-2 (Long Floating-Point)
-
X Specified for internal floating-point items (double precision).
X COMP-2 items are 8 bytes long.
X >_Workstation_> COMP-2 data items are affected by the
X FLOAT(NATIVE|HEX) compiler option. For details, see the IBM COBOL
X Programming Guide for your platform <_Workstation_<
-
X COMPUTATIONAL-3 or COMP-3 (Internal Decimal)
-
X This is the equivalent of PACKED-DECIMAL.
-
X COMPUTATIONAL-4 or COMP-4 (Binary)
-
X This is the equivalent of BINARY.
-
X COMPUTATIONAL-5 or COMP-5 (Native Binary)
-
X >_Workstation_> Under AIX, OS/2, and Windows, this represents native
X binary data. In a COMP-5 binary data item, the total precision of the
X literal (integer and decimal positions) can be up to the maximum value
X that can be accommodated in the number of bytes allocated for the
X binary field (for example, 2, 4, or 8 bytes) rather than conforming to
X the maximum integer and decimal positions specified in the PICTURE
X clause. This is always the native binary data, independent of the
X BINARY compiler option. <_Workstation_<
© Copyright IBM Corp. 1991, 1998
IBM Library Server Copyright 1989, 2005 IBM Corporation. All rights reserved.
Return to library:
z/OS |
z/OS.e |
TPF |
z/VSE |
z/VM |
IBM Hardware |
IBM System z Redbooks
Glossary:
IBM terminology
Publications:
How to order publications
Readers:
Download IBM Library Reader |
Download IBM Softcopy Reader |
Download Adobe® Acrobat® Reader®
Library management:
Download IBM Softcopy Librarian
Contacts:
Contact z/OS
Adobe, the Adobe logo, Acrobat, the Acrobat logo, and Acrobat Reader are registered trademarks
of Adobe Systems incorporated.