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

• Reference modifiers create a unique data item, which is a substring of the data item referenced
by identifier. The program handles this unique data item as an elementary data item
without the JUSTIFIED clause.
When identifier references an alphabetic data item, the unique data item has the class
and category alphabetic.
When identifier references a data item of any other category, the unique data item has
the class and category alphanumeric.
• The unique data item created by reference modifiers can be used not only as a sending item,
but also as a receiving item—you can store a new value into it.
Example 19 Reference Modifiers
A program contains these data descriptions:
01 SPREAD.
03 LTH PIC 99 VALUE 10.
03 MM.
05 FF PIC A(10) VALUE "MARGARINE ".
05 GG PIC $$9.99.
The same program contains these statements:
MOVE 3.15 TO GG
DISPLAY MM
DISPLAY MM (1:LTH)
MOVE "GONE" TO MM (11:)
DISPLAY MM
Executing the program produces these display:
MARGARINE
MARGARINE GONE
Identifiers
An identifier is a data-name made unique by a combination of qualifiers, subscripts, and reference
modifiers.
data-name
is the name of a data item. If it has reference modifiers, it must be USAGE DISPLAY. If it is used
as a subscript or qualifier itself, it can be qualified but not subscripted.
References to Data Items 93