Library View Topics Framed Contents Revised Topics Previous Topic Next Topic Search Search ResultsPrevious Topic MatchNext Topic Match Notes List Notes Print Download No PDF Handheld DisconnectedHandheld ConnectedHelp

X 5.3.16.6 POINTER Phrase




X A data item defined with USAGE IS POINTER is a pointer data item. A
X pointer data item is a 4-byte elementary item,


X You can use pointer data items to accomplish limited base addressing.
X Pointer data items can be compared for equality or moved to other pointer
X items.


X A pointer data item can only be used:


X The USAGE IS POINTER clause can be written at any level except level 88.
X If a group item is described with the USAGE IS POINTER clause, the
X elementary items within the group are pointer data items; the group itself
X is not a pointer data item and cannot be used in the syntax where a
X pointer data item is allowed. The USAGE clause of an elementary item
X cannot contradict the USAGE clause of a group to which the item belongs.


X Pointer data items can be part of a group that is referred to in a MOVE
X statement or an input/output statement. However, if a pointer data item
X is part of a group, there is no conversion of values when the statement is
X executed.


X A pointer data item can be the subject or object of a REDEFINES clause.


X SYNCHRONIZED can be used with USAGE IS POINTER to obtain efficient use of
X the pointer data item.


X A VALUE clause for a pointer data item can contain only NULL or NULLS.


X A pointer data item cannot be a conditional variable.


X A pointer data item does not belong to any class or category.


X The DATE FORMAT, JUSTIFIED, PICTURE, and BLANK WHEN ZERO clauses cannot be
X used to describe group or elementary items defined with the USAGE IS
X POINTER clause.


X Pointer data items are ignored in CORRESPONDING operations.


X A pointer data item can be written to a data set, but, upon subsequent
X reading of the record containing the pointer, the address contained can no
X longer represent a valid pointer.


X Note: USAGE IS POINTER is implicitly specified for the ADDRESS OF special
X register. For more information see the IBM COBOL Programming Guide for
X your platform.

Previous Topic Next Topic © 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.