In the ever-evolving landscape of programming languages, where new languages emerge with the promise of revolutionizing the way we interact with technology, one language stands as a testament to the foundational principles of business computing: the COBOL Programming Language. Short for Common Business-Oriented Language, COBOL’s creation in the late 1950s marked a pivotal moment in the history of computing, establishing conventions and methodologies that continue to influence modern software development.
This article embarks on a journey to explore COBOL, uncovering its origins, evolution, and the unparalleled legacy it has bestowed upon the world of technology. From its syntax that mirrors English to its role in the backend of financial systems, COBOL’s story is one of endurance, adaptability, and, surprisingly, contemporary relevance. Join us as we decode the mysteries of the COBOL programming language, shedding light on why, despite being labeled as antiquated by some, it remains an integral part of today’s digital infrastructure.
Table of Contents:
- What is the COBOL Programming Language?
- COBOL’s Role in Modern Computing
- Understanding COBOL Syntax
- Writing Your First COBOL Program
- Advanced COBOL Features
- COBOL in the Context of Modern Programming
- Learning Resources and Community
- References
1. What is the COBOL Programming Language?
1.1 Origins and History
COBOL, an acronym for Common Business-Oriented Language, emerged in 1959 as a collaborative effort to create a universal programming language that could be used across different hardware systems. It was developed by the Conference on Data Systems Languages (CODASYL), a committee formed by the United States Department of Defense along with industry leaders. Designed to be readable by non-programmers, COBOL’s syntax was heavily inspired by the English language, making it uniquely accessible among its contemporaries.
1.2 Purpose and Design Philosophy
The primary objective behind COBOL’s creation was to facilitate business, finance, and administrative programming for large-scale computers, making data processing jobs more intuitive and less prone to errors. Its design philosophy prioritizes readability and ease of use, aiming to simplify the coding process for complex data processing tasks. This focus on human readability over machine efficiency was revolutionary at the time and has significantly influenced the development of many later programming languages.
1.3 The Structure of COBOL Programs
A typical COBOL program is divided into four main divisions: Identification, Environment, Data, and Procedure, each serving a distinct purpose from defining the program’s metadata to detailing the logic and data manipulation tasks. This structured approach not only aids in maintaining the program but also in understanding and modifying the codebase, highlighting COBOL’s emphasis on longevity and adaptability.
By embarking on this exploration of the COBOL programming language, we aim to appreciate not only its historical significance but also its ongoing relevance in the digital age. Despite its perceived obsolescence, COBOL’s enduring presence in critical systems worldwide speaks volumes about its reliability, efficiency, and the foresight of its creators. As we delve deeper into COBOL’s features, applications, and idiosyncrasies, we uncover a rich legacy that continues to shape the future of programming.
2. COBOL’s Role in Modern Computing
2.1 Industries and Applications
Despite the emergence of newer, more versatile programming languages, COBOL remains deeply entrenched in the infrastructure of numerous industries, most notably finance, government, insurance, and healthcare. It is estimated that over 220 billion lines of COBOL code are still in use today, powering critical systems from banking transactions to public administration. For instance, major banks rely on COBOL for processing daily transactions, highlighting its reliability and efficiency in handling vast amounts of data. Similarly, government agencies use COBOL for managing social security, tax processing, and other administrative functions, underscoring its role in maintaining societal operations.
2.2 COBOL and the Y2K Bug
As the year 2000 approached, the world grappled with the Y2K bug, a programming oversight where dates were represented by just the last two digits of the year. COBOL, being the backbone of many legacy systems, was at the center of this crisis due to its widespread use in systems that had been running for decades. The fear was that when the date rolled over from ’99’ to ’00’, computers would not recognize ’00’ as 2000 but as 1900, leading to erroneous calculations. The global effort to update and debug COBOL systems was monumental, showcasing the programming community’s ability to tackle large-scale challenges and COBOL’s adaptability to contemporary needs.
2.3 The Longevity of COBOL Systems
The longevity of COBOL systems can be attributed to several factors: reliability, efficiency in processing large volumes of transactions, and a design that prioritizes business needs. Many organizations find the cost and risk of migrating away from COBOL to be prohibitive, especially when the existing systems continue to perform effectively. This resilience is a testament to the language’s solid design principles and the foresight of its creators. Moreover, the ongoing efforts to modernize the COBOL programming language, including integrating it with modern interfaces and technologies, ensure its relevance in today’s tech landscape.
To read next: What is an Object-Oriented Programming Language?
3. Understanding COBOL Syntax
3.1 Basic Syntax and Structure
COBOL’s syntax is renowned for its readability, closely mirroring the English language. A COBOL program is organized into a hierarchical structure, starting with the identification division, which provides the program’s name and author, followed by the environment division, specifying the computer and peripheral devices the program will run on. The data division defines the data structures the program will use, while the procedure division contains the program’s executable instructions. This clear structure, combined with its verbose syntax, allows for programs that are understandable even to those with minimal programming experience.
A COBOL program is structured into four main divisions: Identification, Environment, Data, and Procedure. Here’s a simple example:
IDENTIFICATION DIVISION.
PROGRAM-ID. BasicExample.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
SOURCE-COMPUTER. IBM-PC.
OBJECT-COMPUTER. IBM-PC.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 WELCOME-MESSAGE PIC X(20) VALUE 'Hello, COBOL World!'.
PROCEDURE DIVISION.
BEGIN.
DISPLAY WELCOME-MESSAGE.
STOP RUN.
This example defines a program that stores a welcome message and displays it, showcasing the hierarchical structure and syntax of COBOL.
3.2 Data Types and Operations
COBOL supports a range of data types, including numeric (integer and floating-point), alphanumeric (strings of characters), and boolean. One of COBOL’s distinctive features is its support for fixed-point arithmetic, crucial for financial calculations where precision is paramount. Operations in the COBOL programming language cover arithmetic, comparison, and logical operations, allowing for complex data manipulation. The language also supports the definition of complex data structures, facilitating the handling of sophisticated data arrangements required in business applications.
Here’s an example illustrating basic data types and operations with strings and numbers:
IDENTIFICATION DIVISION.
PROGRAM-ID. DataTypesExample.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 NUM1 PIC 9(4) VALUE 1234.
01 NUM2 PIC 9(4) VALUE 5678.
01 SUM PIC 9(5).
01 NAME1 PIC A(15) VALUE 'John'.
01 NAME2 PIC A(15) VALUE 'Doe'.
01 FULL-NAME PIC A(31).
PROCEDURE DIVISION.
BEGIN.
COMPUTE SUM = NUM1 + NUM2.
DISPLAY "Sum: " SUM.
STRING NAME1 DELIMITED BY SIZE
" " DELIMITED BY SIZE
NAME2 DELIMITED BY SIZE
INTO FULL-NAME.
DISPLAY "Full Name: " FULL-NAME.
STOP RUN.
This program demonstrates arithmetic operations with numbers and string concatenation.
3.3 Control Structures and Procedural Programming
Control structures in COBOL include conditional statements (IF…ELSE) and iterative statements (PERFORM), which are used to control the flow of the program based on logic and conditions. COBOL’s procedural nature allows for the modular development of code through the use of subroutines (called paragraphs or sections), enabling code reuse and simplification of complex programs. This procedural paradigm, emphasizing the sequence of operations and decision-making structures, contrasts with the object-oriented approach found in many modern languages but remains effective for the data-intensive processing tasks COBOL is designed for.
Here are examples of conditional statements and subroutines:
IDENTIFICATION DIVISION.
PROGRAM-ID. ControlStructuresExample.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 NUM PIC 9(4) VALUE 10.
PROCEDURE DIVISION.
MAIN-LOGIC.
PERFORM VARYING NUM FROM 1 BY 1 UNTIL NUM > 10
PERFORM CHECK-NUM
END-PERFORM.
STOP RUN.
CHECK-NUM.
IF NUM = 5 THEN
DISPLAY "Number is 5"
ELSE
DISPLAY "Number is not 5".
This example iterates numbers from 1 to 10, checks if the current number is 5, and displays a message accordingly.
By diving into COBOL’s role in modern computing and its syntax, we gain not only a deeper understanding of the language itself but also an appreciation for its continued importance in the digital infrastructure that underpins our society. Despite the allure of modern programming languages, COBOL’s legacy and utility endure, demonstrating the lasting value of its design and the foresight of its creators.
Read also: The BASIC Programming Language.
4. Writing Your First COBOL Program
4.1 Setting Up a Development Environment
To start coding in COBOL, you’ll need to set up a development environment. Fortunately, several modern IDEs and compilers support COBOL, catering to both traditional mainframe development and contemporary platforms. For beginners, GnuCOBOL is a popular, free choice that runs on Windows, Linux, and macOS. To install GnuCOBOL, download it from the official GNU website or use package managers like Homebrew for macOS or apt-get for Linux. Once installed, you can write COBOL code using a basic text editor or an IDE that supports COBOL syntax highlighting for an enhanced coding experience. Configuring your environment properly is crucial for compiling and running your COBOL programs seamlessly.
4.2 Hello, World! Example
A “Hello, World!” program is a traditional way to introduce a new programming language. It demonstrates the basic syntax and capabilities of the language. In COBOL, this program highlights the language’s structured and verbose nature:
IDENTIFICATION DIVISION.
PROGRAM-ID. HelloWorld.
PROCEDURE DIVISION.
DISPLAY 'Hello, World!'.
STOP RUN.
This program consists of the identification division, where you name your program, followed by the procedure division, where the executable instructions reside. The DISPLAY statement outputs text to the console, showcasing COBOL’s straightforward approach to programming tasks.
4.3 Reading and Processing Data
COBOL excels at data processing, making it ideal for business applications. Let’s explore a simple program that reads and processes user input. This example demonstrates basic data handling and arithmetic operations:
IDENTIFICATION DIVISION.
PROGRAM-ID. DataProcessing.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 USER-INPUT PIC 9(4).
01 RESULT PIC 9(5).
PROCEDURE DIVISION.
ACCEPT USER-INPUT.
COMPUTE RESULT = USER-INPUT * 2.
DISPLAY "The result is: " RESULT.
STOP RUN.
This program introduces the data division, where USER-INPUT and RESULT are defined with PIC (Picture) clauses specifying their data types and sizes. The program reads an input, doubles it, and displays the result. Such operations form the backbone of COBOL’s data processing capabilities.
5. Advanced COBOL Features
5.1 Working with Files
File handling is a strength of the COBOL programming language, critical for business applications that process vast amounts of data. COBOL’s file-handling syntax allows for reading, writing, updating, and deleting records in both sequential and indexed files. Here’s a simple example of reading from a sequential file:
IDENTIFICATION DIVISION.
PROGRAM-ID. FileHandler.
DATA DIVISION.
FILE SECTION.
FD INPUT-FILE.
01 INPUT-RECORD PIC X(100).
WORKING-STORAGE SECTION.
01 END-OF-FILE PIC X VALUE 'N'.
88 EOF VALUE 'Y'.
88 NOT-EOF VALUE 'N'.
PROCEDURE DIVISION.
OPEN INPUT INPUT-FILE.
READ INPUT-FILE INTO INPUT-RECORD
AT END SET EOF TO TRUE.
WHILE NOT-EOF
DISPLAY INPUT-RECORD
READ INPUT-FILE INTO INPUT-RECORD
AT END SET EOF TO TRUE.
END-READ.
CLOSE INPUT-FILE.
STOP RUN.
This program demonstrates opening a file, reading records until the end of the file is reached, and closing the file. Handling files efficiently is essential for data-driven COBOL applications.
5.2 Database Integration
Integrating COBOL with databases is crucial for modern applications. COBOL can interact with databases through Embedded SQL (EXEC SQL statements), allowing for operations like querying, updating, and managing data. This integration enables COBOL programs to leverage relational databases for storing and retrieving data, enhancing their capabilities beyond flat-file processing.
The following example demonstrates how to connect to a database, perform a query, and process the results:
EXEC SQL INCLUDE SQLCA END-EXEC.
EXEC SQL WHENEVER SQLERROR GO TO SQL-ERROR END-EXEC.
IDENTIFICATION DIVISION.
PROGRAM-ID. DbExample.
DATA DIVISION.
WORKING-STORAGE SECTION.
EXEC SQL BEGIN DECLARE SECTION END-EXEC.
01 EMPLOYEE-ID PIC 9(5).
01 EMPLOYEE-NAME PIC X(20).
EXEC SQL END DECLARE SECTION END-EXEC.
PROCEDURE DIVISION.
EXEC SQL
CONNECT TO 'SampleDB' USER 'username' IDENTIFIED BY 'password'
END-EXEC.
EXEC SQL
SELECT NAME INTO :EMPLOYEE-NAME
FROM EMPLOYEES
WHERE ID = :EMPLOYEE-ID
END-EXEC.
DISPLAY "Employee Name: ", EMPLOYEE-NAME.
EXEC SQL
DISCONNECT CURRENT
END-EXEC.
STOP RUN.
SQL-ERROR.
DISPLAY "SQL Error occurred".
STOP RUN.
This COBOL program uses Embedded SQL to connect to a database named ‘SampleDB’, queries for an employee’s name by their ID, and then disconnects from the database.
5.3 Error Handling and Debugging
Error handling in COBOL is managed through the use of condition names, the INVALID KEY clause for file operations, and the USE statement for exception handling. Debugging COBOL code traditionally relies on diagnostic messages, runtime checks, and debugging tools provided by COBOL compilers or IDEs. Understanding and implementing robust error handling and debugging practices are vital for developing reliable COBOL applications.
6. COBOL in the Context of Modern Programming
6.1 Comparisons with Contemporary Languages
COBOL stands in stark contrast to modern programming languages such as Python, Java, and JavaScript in several aspects, including syntax, usage, and application domains. COBOL’s verbose syntax, designed for readability and straightforward business logic implementation, differs significantly from the concise and flexible syntax of languages like Python. While Java and JavaScript are widely used for web and mobile applications, COBOL’s stronghold remains in legacy systems, particularly in the financial and governmental sectors. This distinction underscores COBOL’s specialization in batch processing and transaction processing systems, where reliability and precision are paramount.
6.2 COBOL’s Contributions to Programming Language Design
Despite its age, COBOL’s influence on programming language design is undeniable. Its introduction of clear, English-like syntax aimed at making code understandable for non-programmers has inspired the development of many user-friendly programming languages. COBOL’s structured programming approach, emphasizing a logical flow of procedures, has also contributed to the evolution of software development methodologies, promoting readability and maintainability in code.
6.3 The Future of COBOL in Software Development
The future of COBOL in software development remains secure, anchored by its critical role in mainframe computing and vast legacy codebases. Efforts to modernize the COBOL programming language, through integration with modern systems and the introduction of object-oriented features, are ensuring its adaptability. Furthermore, the scarcity of skilled COBOL programmers has rekindled interest in the language, leading to new opportunities for developers willing to learn and maintain COBOL systems. As businesses continue to rely on COBOL for their core operations, its presence in the programming world will persist, blending legacy strength with modern technology.
7. Learning Resources and Community
7.1 Official Documentation and Tutorials
For those looking to dive into COBOL programming, official documentation and tutorials serve as invaluable resources. The IBM Knowledge Center and Micro Focus documentation offer comprehensive guides on COBOL syntax, features, and best practices. Beginners can start with online tutorials and interactive learning platforms like Codecademy or Coursera, which provide structured COBOL courses ranging from basic syntax to advanced programming concepts.
7.2 Communities and Forums
The COBOL programming community is active and welcoming, with forums and discussion groups available for programmers of all levels. Websites such as Stack Overflow and Reddit host vibrant COBOL communities where individuals can ask questions, share knowledge, and discuss the nuances of COBOL programming. Additionally, LinkedIn groups and specialized online forums offer spaces for COBOL developers to connect, share job opportunities, and keep up with industry trends.
7.3 Further Reading and Courses
For those seeking to deepen their understanding of COBOL, numerous books and online courses provide detailed insights into the language. “Beginning COBOL for Programmers”(1) by Michael Coughlan offers a modern perspective on COBOL programming, while “Murach’s Mainframe COBOL”(2) is a classic textbook that covers the essentials. Online platforms such as Udemy and Pluralsight feature courses taught by industry experts, catering to both beginners and experienced programmers looking to refine their COBOL skills.
8. References
To ensure the accuracy and reliability of the information provided in this article, the following references have been utilized:
- “Beginning COBOL for Programmers” by Michael Coughlan
- “Murach’s Mainframe COBOL” by Anne Prince
- “COBOL for the 21st Century” by Nancy Stern, Robert A. Stern, and James P. Ley
- “The early history of COBOL“, Jean E. Sammet (Paper published on June 1978)