cobol_for_the_21st_century

COBOL for the 21st Century Preface
Fair Use Sources

COBOL for the 21st Century Preface

Return to COBOL for the 21st Century, COBOL bibliography, COBOL, COBOL DevOps, COBOL glossary, Awesome COBOL, Awesome IBM Mainframe, IBM Mainframe development, IBM Mainframe bibliography, Fortran, Fortran glossary

“ (Cbl21stC 2006)

PREFACE

INTENDED AUDIENCE This book is intended for readers with no previous programming or computer experience as well as for those with some background in the computing field. It has been specifically designed for use in college courses on COBOL both in two-year and four-year schools.

SIGNIFICANCE OF COBOL AS A PROGRAMMING LANGUAGE FOR THE 21ST CENTURY

For many years, there has been a great deal of controversy regarding COBOL as a viable programming language. Many people think that a language developed around 1960 is not likely to have the necessary components to make it operate efficiently and effectively on today's computers.

The issue became a critical one in the late 1990s when information technology professionals began to pay close attention to the fact that the year 2000 was fast approaching and COBOL code typically represented years as two digits (89 would be a short version for 1989). This two-digit designation would lose its validity in 2000 since it would not be clear whether a date was 20xx or 19xx. This problem threatened to wreak havoc on all current COBOL code and the ”Y2K“ (an abbreviation for the Year 2000) Problem became a major concern of companies and governments worldwide.

The impending crisis not only threatened to have serious ramifications in the business world, but it motivated many people to stockpile food since they feared that shipping dates on inventories would be impacted. Fortunately, the problem was corrected by current COBOL programmers and those enticed out of retirement. The Y2K Problem became the biggest nonevent of the turn of the century.

But it did focus attention on the number of COBOL programs still widely used today. The information technology field was stunned at the amount of code that was functioning, and functioning well, after 20, 30, even 40 years. This has resulted in a resurgence of interest in teaching the language to students. The following facts lend credence to the belief that COBOL is likely to remain a major language in the years ahead.

Did You Know That…

Applications managing about 85 percent of the world's business data are written in COBOL. [1]

There are approximately 90,000 COBOL programmers in the United States. [2]

The annual growth of COBOL code over the next four years is projected to be five billion lines. [3]

There are up to 200 billion lines of COBOL code running production applications worldwide. [4]

It has been estimated that 35 percent of all new business application development is written in COBOL. [5]

For the U.S. Department of Defense, 59 percent of information systems applications use COBOL. [6]

In summary, for those who have suggested that COBOL is a dying language, these facts should put to rest that belief.

OBJECTIVES OF THIS BOOK

To teach students how to design programs so that they are easy to read, debug, modify, and maintain.

To provide students with the ability to write well-designed elementary, intermediate, and advanced structured COBOL programs in their entirety. These include both batch and interactive programs.

COBOL affords a unique opportunity to learn how to write interactive programs as well as batch programs with sophisticated file processing techniques. We give equal weight to both types of programs so that they continue to work efficiently and effectively.

To familiarize students with information processing and systems concepts that will help them interact with users and systems analysts when designing programs.

To focus on the key elements of the most recent major COBOL standard, called COBOL 85, that facilitate and promote the writing of well-designed structured programs. We highlight where COBOL 85 features differ from COBOL 74, the previous standard. We also focus on functions that were introduced in 1989 as extensions to the 1985 standard. Finally, we specify changes that will be incorporated in the next standard, which is currently referred to as COBOL 2008.

To familiarize students with programming design tools such as pseudocode and hierarchy charts that make program logic more structured, modular, and top-down.

To teach students useful techniques for maintaining and modifying older ”legacy“ programs.

To keep students aware of the controversy surrounding COBOL regarding its age, and to attempt to dispel notions of the impending demise of the language.

HIGH LIGHTS OF THIS EDITION

The eleventh edition of this book includes the following features:

Case Study.

There is a case study that includes programs students will need to write to have the case function properly and completely. The case study is on hot air balloon rides. It appears at the end of each unit.

Updated Coding — COBOL 85 and COBOL 2008 are the two main standards taught here.

We continue to emphasize COBOL 85 coding, while providing a very limited discussion of the older COBOL 74 code. COBOL 2008 changes are discussed, where appropriate, throughout each chapter.

To facilitate the reader's understanding of these three standards, we use icons to highlight a feature that specifically relates to a particular standard:

HIGH LIGHTS OF THIS EDITION Internet resources related to COBOL are provided throughout the text.

Because such resources are constantly changing, we provide discussions throughout the text on how students can use search engines and other tools to locate various COBOL sites. Throughout the text, Web sites that contain important COBOL information are cited.

References in the text that point to Web sites include a Net icon:

HIGH LIGHTS OF THIS EDITION More material on intrinsic functions, validating interactive programs, indexed disk file processing, and relative disk file processing has been added.

Chapter 7 includes more intrinsic functions and discusses all such functions very thoroughly. Also, later chapters have programming assignments that reinforce the use of intrinsic functions.

Chapter 11 focuses on data validation for both interactive and batch programs.

Discussions have been expanded on the START statement, DYNAMIC access of files, FILE STATUS codes, and ALTERNATE RECORD KEYS.

Improved pedagogy.

The basic pedagogic approach and teaching tools used in previous editions have been maintained. We have revised end-of-chapter questions to make them more current and have added new Programming Assignments.

In addition, we have added debugging tips and critical thinking questions to each chapter.

We have also eliminated some repetitive material — examples as well as narrative.

Each chapter includes Internet assignments to familiarize students with sites that can be used to enhance their COBOL skills.

New in this edition.

More material has been provided on multiple-level tables and arrays without inundating students with more material than they could possibly handle.

Screen layouts and interactive programming have been emphasized. In Chapter 6, we introduce the SCREEN SECTION and illustrate how users can create fully interactive programs. From Chapter 6 on, every chapter includes interactive elements and at least one end-of-chapter Programming Assignment that requires interactive processing.

The Report Writer Module has been added to the book as Chapter 17.

FEATURES OF THE TEXT

Format

The format of this text is designed to be as helpful as possible. Each chapter begins with:

A detailed chapter outline.

Before beginning a chapter, you can get an overview of its contents by looking at this outline. In addition, after you have read the chapter, you can use the outline as a summary of the overall organization.

A list of objectives.

This list helps you see what the chapter is intended to teach even before you read it.

The material is presented in a step-by-step manner with numerous examples and illustrations. Within each chapter there are self-tests, with solutions, that are designed to help you evaluate your own understanding of the material presented. We encourage you to take these tests as you go along. They will help pinpoint and resolve any misunderstandings you may have.

End-of-Chapter Material

Each chapter ends with learning aids consisting of:

Chapter Summary.

Key Terms List. This is a list of all new terms defined in the chapter. Appendix C is a glossary that lists all key terms in the text along with their definitions.

Chapter Self-Test — with solutions so you can test yourself on your understanding of the chapter as a whole.

Practice Program. A full program is illustrated. We recommend you read the definition of the problem and try to code the program yourself. Then compare your solution to the one illustrated.

Review Questions. These are general questions that may be assigned by your instructor for homework. They include questions that require you to access the Internet for reference.

Debugging Exercises. These are program excerpts with errors in them. You are asked to correct the coding. The errors highlighted are those commonly made by students and entry-level programmers.

Programming Assignments. The assignments appear in increasing order of difficulty. They include a full set of specifications similar to those that programmers are actually given in the ”real world.“ You are asked to code and debug each program using test data. You will need to either create your own test data or receive a set from your instructor.

Programming Assignments in each chapter include interactive programs, as well as batch programs, and a maintenance program that students are assigned to modify or update.

A syntax reference guide accompanies this text. Data sets for all Programming Assignments and all programs illustrated in the book can be downloaded from the Internet.

INSTRUCTIONAL AIDS

Instructor Supplements

INSTRUCTOR'S RESOURCES WEB SITE. All Instructor Supplements listed below will be available in electronic form on the Instructor's Resources Web site located at www.wiley.com/college/stern.

INSTRUCTOR'S MANUAL. This manual contains Chapter Objectives and Lecture Outlines. It also contains Solutions to Review Questions (which include True-False, Fill-in-the-Blank, General Questions, Interpreting Instruction Formats, and Suggestions for Validating Data), and Solutions to Debugging Exercises.

SOLUTIONS TO PROGRAMMING ASSIGNMENTS by James P. Ley, University of Wisconsin–Stout (Emeritus). The Solutions Manual contains solutions to the Programming Assignments, copies of the Practice Programs, and the data sets along with a README.TXT file. All the programs have been compiled and executed. The sample input and corresponding output are provided as well.

TEST BANK. The Test Bank contains over 1,000 questions. True-False, Fill-in, Short Answer, Multiple Choice, and Problem-Solving questions provide an excellent resource for instructors who create their own exams.

COMPUTERIZED TEST BANK. This supplement provides an electronic version of the Test Bank that enables instructors to customize material when creating exams for students.

POWERPOINT SLIDES. The PowerPoint slides consist of figures and illustrations from the text combined with outlines of key concepts from each chapter. They are designed to enhance lectures and serve as a study tool for students.

Student Supplements PROGRAMS AND DATA by James P. Ley, University of Wisconsin–Stout (Emeritus). The Practice Programs from the text along with the data for the Practice Programs and the Programming Assignments can be downloaded from the Internet.

SYNTAX REFERENCE GUIDE by Nancy Stern and Robert A. Stern. This Syntax Guide is a brief, standalone booklet that students can use for quick and convenient reference. It is packaged at no cost in the back of all new copies of the text.

INTERACTIVE SCREEN DISPLAYS. Examples of interactive screen displays (identified with figure numbers T1, T2, etc.) are discussed throughout the text. The following icon is used to indicate that these screen displays can be downloaded from the Internet:

www.wiley.com /college/stern

The following PC compiler is available with the text:

Micro Focus NetExpress. This compiler is distributed by John Wiley & Sons only to colleges and universities in North America. To obtain this compiler outside of North America, please contact Micro Focus Academic Programs, 701 East Middlefield Road, Mountain View, CA 94043 or www.microfocus.com.

The compiler has on-line documentation.

For online help, an email address (tech help@wiley.com) is available for faculty only who may experience difficulty installing or using this compiler. If you are a student, please ask your instructor for help.

COBOL Web Site Wiley's Web site for this book is www.wiley.com/college/stern; it contains late-breaking information as well as supplements that can be downloaded, and linkages to other COBOL sites.

The reviewers who provided many helpful suggestions throughout the development of this project are acknowledged on page xii, along with all of those who helped bring this project to fruition.

We update our programming texts every few years and welcome your comments, criticisms, and suggestions. We can be reached c/o:

Nancy Stern

Robert A. Stern

BCIS Department

Hofstra University

Hempstead, NY 11550

E-mail: nancy.stern@hofstra.edu

James P. Ley (Emeritus)

Department of Mathematics, Statistics, and Computer Science

University of Wisconsin-Stout

Menomonie, WI 54751

E-mail: leyj@uwstout.edu