Learn COBOL-VARIANTS with Real Code Examples

COBOL is primarily used for business data processing, batch jobs, and mainframe applications.

Variants exist due to historical, platform, and vendor-specific adaptations.

Supports procedural programming with some object-oriented features in modern variants.

Designed for readability and maintainability in large-scale enterprise systems.

Critical for financial institutions, government agencies, and legacy enterprise systems.

DIVISION-based program structure (IDENTIFICATION, ENVIRONMENT, DATA, PROCEDURE)

File and record handling for large datasets

Compatibility with mainframes and legacy systems

Strong support for fixed-point decimal arithmetic

Ability to call external libraries or services

Divisions: IDENTIFICATION, ENVIRONMENT, DATA, PROCEDURE

Sections and paragraphs for modular logic

Data types: numeric, alphanumeric, decimal

File handling: sequential, indexed, relative

Control flow: IF, PERFORM, EVALUATE, GOTO

SOURCE COBOL program files (.cbl, .cob)

Copybooks for reusable data definitions

Batch job scripts or JCL for execution

Testing scripts for unit verification

Documentation for legacy system understanding

Identify the business logic to automate

Define input and output files or datasets

Write procedures in the PROCEDURE DIVISION

Compile and test incrementally

Integrate with existing batch jobs or services

Beginner: simple arithmetic and file processing

Intermediate: conditional logic and reporting

Advanced: indexed file management and transaction processing

Expert: mainframe batch job orchestration and DB2 integration

Architect: large-scale enterprise system maintenance and modernization

IBM COBOL vs Micro Focus COBOL: platform and modern features differ

Batch vs Online COBOL: batch for jobs, online for transaction processing

Procedural vs Object-Oriented COBOL: OO-COBOL for modern design

COBOL vs Java/C#: verbose but highly stable; modern languages more flexible

Legacy COBOL vs Modern COBOL: modern variants support GUI, APIs, and OO features

1959 - COBOL developed by CODASYL and Grace Hopper

1960s - Early compiler implementations

1970s - Standardization by ANSI

1980s - Object-oriented extensions proposed

1990s - Modern vendor variants (IBM, Micro Focus) emerge

2002 - COBOL 2002 standard introduces OO features

2014 - COBOL for .NET and Java integration

2025 - Active maintenance in legacy systems and modernization projects

Copybook - reusable code/data definitions

Paragraph - named block of code

Section - group of paragraphs

Indexed File - file with key-based access

EVALUATE - COBOL equivalent of switch/case