Introduction

COBOL (Common Business Oriented Language) is one of the oldest high-level programming languages still in use today. Developed in the 1950s by a team at Remington Rand, COBOL was designed to be a business-oriented language that could handle complex data processing tasks with ease.

History

COBOL’s development began in 1959 and was initially intended for use on mainframe computers. The first version of COBOL was released in 1960 and was based on the Short Code compiler developed by IBM. Over the years, several revisions have been made to the language, with each new release introducing new features and improvements.

Features

COBOL is a high-level language that is designed for business applications. It has several key features that make it an attractive choice for many developers:

• Procedural Programming: COBOL supports procedural programming, which allows developers to break down complex programs into smaller, more manageable tasks.
• Structured Programming: COBOL also supports structured programming, which makes it easier to write and maintain large programs.
• Data Validation: COBOL provides a range of features for validating data, including input validation, output validation, and file validation.
• Exception Handling: COBOL includes built-in support for exception handling, which allows developers to catch and handle errors in their code.

Syntax

COBOL’s syntax is unique and based on English-like statements. This makes it easy to read and understand, even for developers who are new to the language. Here are some of the key components of COBOL’s syntax:

• Identifier: An identifier is a word or phrase that identifies a variable, program, or function.
• Literal: A literal is a constant value that can be used in a program.
• Expression: An expression is a combination of identifiers and literals that evaluates to a value.

Example

Here’s an example of a simple COBOL program:

IDENTIFICATION DIVISION.
PROGRAM-ID. HELLO-WORLD.

DATA DIVISION.
WORKING-STORAGE SECTION.
01  GREETING  PIC X(10).

PROCEDURE DIVISION.
MAIN-PROGRAM.
DISPLAY 'Hello, world!'

Control Structures

COBOL includes several control structures that allow developers to control the flow of their programs:

• IF Statement: The IF statement allows developers to execute a block of code if a condition is true.
• ELSE Statement: The ELSE statement allows developers to execute an alternative block of code if the original condition is false.
• CASE Statement: The CASE statement allows developers to execute different blocks of code based on specific conditions.

Loops

COBOL includes several loop statements that allow developers to repeat a block of code:

• DO Loop: The DO loop allows developers to repeat a block of code a specified number of times.
• PERFORM Loop: The PERFORM loop allows developers to repeat a block of code until a condition is met.

Files

COBOL includes several features for working with files, including:

• FILE-CONTROL Statement: The FILE-CONTROL statement allows developers to specify how data will be written to or read from a file.
• OPEN Statement: The OPEN statement allows developers to open a file for reading or writing.

Advantages

COBOL has several advantages that make it an attractive choice for many developers:

• Maturity: COBOL is one of the oldest programming languages still in use today, which means it has been extensively tested and refined.
• Portability: COBOL programs can be run on a variety of platforms, including mainframes, minicomputers, and PCs.
• Scalability: COBOL programs can handle complex data processing tasks with ease.

Disadvantages

While COBOL has many advantages, it also has several disadvantages:

• Steep Learning Curve: COBOL’s syntax is unique and based on English-like statements, which can make it difficult for developers to learn.
• Limited Support: While COBOL is still widely used today, its popularity has declined in recent years, which means support and resources may be harder to come by.

Conclusion

COBOL is a high-level programming language that is designed for business applications. Its unique syntax and features make it an attractive choice for many developers, but its steep learning curve and limited support may deter others. Whether you’re just starting out with COBOL or are looking for a way to modernize your legacy code, this guide has provided you with the information you need to get started.

Appendix

Here’s some additional information about COBOL that may be helpful:

• COBOL Compiler: A COBOL compiler is required to compile and run COBOL programs.
• COBOL Interpreter: A COBOL interpreter can be used to execute COBOL programs without compiling them first.

Glossary

Here’s a list of terms related to COBOL that you may find useful:

Term	Definition
Identifier	A word or phrase that identifies a
	variable, program, or function.
Literal	A constant value that can be used in
	a program.
Expression	A combination of identifiers and
	literals that evaluates to a value.

Note: The above glossary is not exhaustive and is meant to provide a brief overview of the terminology used in COBOL.