COBOL Manual for TNS/E Programs (H06.08+, J06.03+)

◦ Elementary items whose data description entries contain SIGN, JUSTIFIED, or BLANK
WHEN ZERO clauses
◦ See Trapping Size Errors under PICTURE Clause (page 191).
• INDEX Data Items
The description of a group or elementary data item with INDEX format cannot include any of
these clauses:
◦ PICTURE
◦ VALUE
◦ SYNCHRONIZED
◦ JUSTIFIED
◦ BLANK WHEN ZERO
An index data item description cannot be followed immediately by any level-88 items; that
is, an index data item cannot serve as a conditional variable.
The compiler stores each INDEX data item as 4 bytes, aligned on a 4-byte boundary.
• NATIVE-n Data Items
The description of a group or elementary data item with NATIVE-n format cannot include any
of these clauses:
◦ PICTURE
◦ SYNCHRONIZED
◦ JUSTIFIED
◦ BLANK WHEN ZERO
◦ SIGN
If an arithmetic statement includes a SIZE ERROR phrase, the size error condition occurs as
defined in SIZE ERROR Phrase (page 244), except that in a NATIVE-n receiving item the test
is for truncation of significant bits, not significant decimal digits.
If a NATIVE-n data item used as a receiving operand specifies the ROUNDED phrase, decimal
(not binary) rounding occurs, as described in SIZE ERROR Phrase (page 244).
Because COBOL limits literals to a length of 18 digits, the maximum value that you can assign
to a NATIVE-8 data item (by initialization with a VALUE phrase or by a MOVE statement, for
example) is the 18-digit value of -/+999999999999999999, rather than the maximum
storable 19-digit value of -9223372036854775808 or +9223372036854775807.
• How NATIVE-n and BINARY/COMPUTATIONAL Formats Differ
The significant difference between a NATIVE-n data item (which occupies n character positions
by definition) and a COMPUTATIONAL data item that happens to occupy n character positions
is that the COMPUTATIONAL item has the number of decimal digits declared by its PICTURE
clause. Although a NATIVE-n data item and a certain COMPUTATIONAL data item both
occupy n character positions, they cannot necessarily assume the same set of values.
For example, a NATIVE-2 data item and a COMPUTATIONAL data item with PICTURE 9999
both occupy 2 character positions, but any value larger than 9999 is truncated on the left
before it is assigned to the COMPUTATIONAL data item, whereas the NATIVE-2 data item
can be assigned any value in the range -32768 through +32767.
Descriptions of Records (Levels 01-49) 209