Micro Focus Object COBOL™

OO Programming with Object COBOL

MERANT™

Issue 4a
August 1999

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Preface

This book explains how you use Micro Focus OO extensions to COBOL for Object-oriented programming. It includes explanations of concepts, programming tutorials, programming documentation and information about the Micro Focus Class Library.

Audience

You should be familiar with the COBOL language and with your operating system. You should read the Getting Started book and be familiar with the COBOL development cycle described in the User Guide before reading other books in the book set.

Environments

Micro Focus COBOL systems are available for DOS, Windows, Windows 95, Windows NT, and OS/2 V2.1 or later, and for many varieties of UNIX. Both 32-bit and 16-bit versions are available (16-bit is not available on UNIX).

Some of the books supplied with this COBOL system are generic across all these environments. Other books are specific to your operating system, but might contain some generic chapters. The chapter Welcome! in the Getting Started book explains this in detail.

Conventions

In the books, unless otherwise stated:

• References to Windows apply to Windows 3.1 or later (running the 16-bit COBOL system), and to Windows 95 and Windows NT (running the 16-bit and 32-bit COBOL systems).

• References to OS/2 apply to all supported versions of OS/2 (running the 16-bit and 32-bit COBOL systems).

• References to Windows NT apply to Windows 95 and Windows NT (running the 32-bit COBOL system).

• References to DOS apply to both IBM Personal Computer DOS and MS-DOS.

• References to UNIX apply to all operating systems that are compatible with UNIX System V, Release 3.0 or later, complying with the System V Interface Definition (SVID).

Side Headings

In a generic book or chapter, text that does not apply to all supported environments and COBOL systems is marked by a side heading in the left margin. A side heading applies to the paragraph it is next to, unless it is next to the first paragraph in a section, in which case it applies to that whole section.

The following examples of side headings show what they mean:

UNIX:
This text applies to the 32-bit COBOL system on UNIX.

DOS, Windows and OS/2:
This text applies to the 16-bit or 32-bit COBOL system on DOS, Windows, Windows 95, Windows NT, and OS/2 V2.1 or later.

16-bit:
This text applies to the 16-bit COBOL system on DOS, Windows, Windows 95, Windows NT, and OS/2 V2.1 or later.

32-bit:
This text applies to the 32-bit COBOL system on UNIX, Windows 95, Windows NT, and OS/2 V2.1 or later.

32-bit for Windows NT and OS/2:
This text applies to the 32-bit COBOL system on Windows 95, Windows NT, and OS/2 V2.1 or later.

Notation

The notation used in the books is as follows:

• Enter refers to the carriage-return or Enter key. Where commands to be typed are shown, the Enter key is not shown. It is treated as implicit that the Enter key must be pressed at the end of the line.

• Hexadecimal numbers are enclosed in quotation marks and preceded by a lower-case "x" or "h"; for example, x"9D", h"03FF". The "x" is used when the hexadecimal number represents a character string; the "h" when it represents a numerical value.

• With COMP-X and COMP-5, PIC X is used rather than PIC 99. Unlike PIC 99, PIC X shows the length of the data item directly and so demonstrates more clearly the use of COMP-X, which is to define a binary item of the specified number of bytes.

Command Lines

The notation used to describe the format of command lines is as follows:

• Words printed in italics are generic terms representing names to be devised by you.

• Words printed in nonitalic characters are the actual words you must enter.

  DOS, Windows and OS/2:
  On DOS, Windows and OS/2 you can type them in upper, lower, or mixed case except where otherwise stated.

  UNIX:
  On UNIX you must type them in upper or lower case as shown.

• Square brackets [ ] mean the material inside them is optional.

• Braces { } mean you must choose from the options inside them. If there is only one option in the braces, they mean repetition.

• An ellipsis (...) following { } or [ ] means you can repeat the material inside them. The number of repetitions allowed is unlimited unless otherwise stated. Square brackets [ ] with an ellipsis mean you can omit the material altogether.

• If a command line does not fit across the page, it is continued on the next line; the continuation line is indented.

• UNIX:
  On UNIX, the books may refer you to the Release Notes for details specific to a particular UNIX platform.

• UNIX:
  On UNIX, all command line formats and examples are for the standard UNIX shell, the Bourne shell. If you are using another shell, see your UNIX documentation for the appropriate formats.

• UNIX:
  Where examples showing environment variables do not specifically show them being exported to the shell, it is treated as implicit that they are exported.

• UNIX:
  Some keystrokes using function keys or the Alt or Ctrl keys are not available on all UNIX platforms. The User Guide contains a UNIX Key Usage Chart, listing how the keystrokes shown in the books map onto actual keystrokes.

Notes

• F1=Help appears on every menu in character-mode Micro Focus software. It invokes a help screen describing the current menu. F1=Help is not described in the documentation.

• What appears on your screen may differ in minor ways (for example, version numbers) from that illustrated in the books. This will not affect the operation of your software.

About this Book

OO Programming with Object COBOL shows you how to write object-oriented programs using Micro Focus Object COBOL. Most of the book is generic, and the material applies equally to Windows, OS/2 and UNIX platforms. Exceptions are marked as explained in the Conventions and Side Headings section of this preface. Where an entire chapter is specific to particular environments, this is indicated in the chapter title.

This manual:

• Introduces you to the Micro Focus support for object-orientation (OO).

• Provides a reading-list for newcomers who want to learn about the principles of OO.

• Provides a set of tutorials which teach you how to develop programs using the Object COBOL language and class library. Because the Windows and OS/2 environments are different to UNIX, Part II of this manual contains Windows and OS/2 tutorials, and Part III contains UNIX tutorials.

• Describes how you can both use Object COBOL classes in COBOL programs, and how to write your own.

• Describes the Micro Focus Class Library frameworks.