COBOL programming
COBOL (Common Business-Oriented Language) is a high-level programming language designed
primarily for business, finance, and administrative systems. It was first
introduced in 1959 and became one of the most widely used languages in areas
where data processing is critical, such as banking, insurance, and government
applications.
1. Business-Oriented : COBOL was specifically
created for business applications and data processing, rather than scientific
or systems programming. It's well-suited for handling large volumes of data,
which is common in financial and administrative systems.
2. Readable and Self-Documenting : COBOL uses
English-like syntax, making it more readable and easier to understand than many
other programming languages, especially for non-technical users. For example,
keywords like `ADD`, `SUBTRACT`, `MOVE`, and `DISPLAY` make the code highly
descriptive.
3. Structured Programming : While older versions
of COBOL supported unstructured code with the heavy use of `GOTO` statements,
modern COBOL has evolved to include structured programming concepts like `IF`,
`PERFORM` (looping), and `EVALUATE` (switch-case logic).
4. Legacy Systems : COBOL is considered a
"legacy" language, but it is still in widespread use today,
particularly in mainframe environments where massive data processing and
record-keeping systems are critical. Many older systems are still written in
COBOL, leading to a high demand for COBOL programmers in specific industries.
5. File Handling and Reporting : COBOL excels at
file manipulation and generating reports from data, making it ideal for tasks
like payroll processing, transaction records, and other financial operations.
1. IDENTIFICATION DIVISION : Provides basic
information about the program, such as its name and author.
2. ENVIRONMENT DIVISION : Describes the hardware
and operating system requirements, like input/output device details.
3. DATA DIVISION : Defines the variables,
constants, and data structures the program will use.
4. PROCEDURE DIVISION : Contains the logic and
actual code for manipulating data and performing operations.
Example COBOL Program: Adding Two Numbers
```cobol
IDENTIFICATION DIVISION.
PROGRAM-ID. AddTwoNumbers.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 NUM1 PIC 9(3) VALUE 0.
01 NUM2 PIC 9(3) VALUE 0.
01 RESULT PIC 9(4) VALUE 0.
PROCEDURE DIVISION.
DISPLAY "Enter first number: ".
ACCEPT NUM1.
DISPLAY "Enter second number: ".
ACCEPT NUM2.
ADD NUM1 TO NUM2 GIVING RESULT.
DISPLAY "The result is: " RESULT.
STOP RUN.
```
- IDENTIFICATION DIVISION : This division tells
us that the program's name is "AddTwoNumbers."
- ENVIRONMENT DIVISION : In this simple example,
there are no special hardware or OS requirements, so it's left blank.
- DATA DIVISION : We define three variables,
`NUM1`, `NUM2`, and `RESULT`, with specific picture (PIC) clauses. The PIC
clause specifies the format of the variables (`9(3)` means a 3-digit number).
- PROCEDURE DIVISION : The logic of the program.
The user is prompted to input two numbers, they are added together, and the
result is displayed.
COBOL Syntax Elements:
1. Variables : Declared in the `DATA DIVISION`
using the `PIC` (Picture) clause to specify the size and type. For example,
`PIC 9(3)` represents an integer with 3 digits, while `PIC X(10)` represents a
string with 10 characters.
2. Arithmetic Operations : COBOL uses commands
like `ADD`, `SUBTRACT`, `MULTIPLY`, `DIVIDE`, and `COMPUTE`. The results of
these operations can be stored in a variable or directly displayed.
```cobol
IF NUM1 > NUM2 THEN
DISPLAY "NUM1 is greater than
NUM2."
ELSE
DISPLAY "NUM1 is less than or equal
to NUM2."
END-IF.
```
4. Loops : COBOL uses `PERFORM` to create loops.
You can repeat a set of instructions for a fixed number of times or until a
condition is met.
```cobol
PERFORM TIMES-10
DISPLAY "Loop iteration: " I.
ADD 1 TO I.
END-PERFORM.
```
COBOL in the Modern World:
Despite being over 60 years old,
COBOL is still actively used in critical industries, especially in financial
institutions and government systems where reliability and stability are
paramount. Many banks, insurance companies, and governments still use COBOL to
run their core systems, often on mainframe computers. These systems process
billions of transactions daily, and rewriting them in a modern language would
be extremely costly and risky, leading to the continued demand for COBOL expertise.
While it's not as trendy as
languages like Python or Java, the ability to maintain and enhance COBOL-based
systems is a valuable skill, especially as many COBOL experts retire, creating
a need for new programmers to manage legacy systems.
- It has a highly readable
syntax, which makes it accessible for both developers and business analysts.
- COBOL is still widely used in industries
where stable, large-scale transaction processing systems are required, and it
has a specific strength in handling data files and generating reports.
=====
Yes, COBOL is still widely used in industries,
particularly in sectors that rely on large-scale transaction processing and
data management systems. Despite being over 60 years old, COBOL remains crucial
for many organizations due to its stability, efficiency, and the significant
role it has played in the development of critical business applications over
the decades.
Key Industries Where COBOL is Still Widely Used:
1. Banking and
Financial Services :
- COBOL
powers the backend of many banks and financial institutions worldwide. It is
used for tasks such as handling transactions, managing customer accounts,
generating statements, and supporting ATMs. Large-scale operations, such as
processing billions of daily transactions, are often managed using COBOL
because of its reliability and performance with large data volumes.
2. Insurance :
- Insurance companies use COBOL for policy management, claims processing, underwriting, and premium calculations. The long-term nature of insurance policies makes COBOL systems ideal, as they require stability and the ability to store and retrieve data reliably over extended periods.
3. Government
Systems :
- Many
government agencies still rely on COBOL for critical systems related to
taxation, social security, and unemployment benefits. For instance, the U.S.
Social Security Administration and IRS use COBOL to manage vast datasets
related to citizens' financial and personal records.
- COBOL systems are deeply embedded in public sector infrastructure because they have proven dependable over the decades.
4. Retail and
Manufacturing :
- COBOL plays a significant role in supply chain management, inventory control, and point-of-sale (POS) systems. Many large retailers and manufacturing companies rely on COBOL-based systems for managing orders, stock, and logistics.
5. Airlines and
Transportation :
- The airline industry uses COBOL for reservation systems, ticketing, flight scheduling, and other logistics operations. Many legacy systems in the travel and transportation industry are built on COBOL because of the large amount of data involved and the need for high transaction throughput.
Why COBOL Continues to Be Used:
1. Legacy
Systems :
- Many
organizations invested heavily in COBOL systems decades ago, and these systems
have proven to be reliable, efficient, and scalable. Rewriting or replacing
these systems would be risky, expensive, and time-consuming, as they handle
mission-critical operations.
- In many cases, businesses and governments have found that maintaining and updating existing COBOL systems is more cost-effective than attempting a full system migration to a modern language.
2. Stability
and Reliability :
- COBOL is
known for its robustness and ability to process large volumes of transactions
without failure. This is vital in sectors like finance, where system downtime
can lead to huge financial losses.
- Over time, COBOL systems have evolved to handle new requirements, but they retain their core strengths of performance and reliability.
3. Performance
with Large-Scale Data Processing :
- COBOL is excellent at handling batch processing, making it ideal for tasks that require the processing of millions or even billions of records at once, such as payrolls, banking transactions, and insurance claims.
4. Mainframe
Compatibility :
- COBOL runs on mainframes , which are still heavily used by large corporations for critical business applications. Mainframes are known for their ability to handle massive workloads and their long uptime (sometimes running for years without interruption). As COBOL was designed to work efficiently on mainframes, it remains the go-to language for mainframe applications.
5. Long
Lifespan of Business Systems :
- Business systems, especially in banking, insurance, and government, tend to have very long lifecycles. COBOL systems, many of which were built in the 1960s and 1970s, have been running for decades and are still fulfilling the needs of these organizations without major failures.
Challenges and Modernization Efforts:
1. Lack of
COBOL Programmers :
- As COBOL
was developed decades ago, many of the original COBOL programmers are retiring.
This has led to a shortage of skilled professionals capable of maintaining and
updating COBOL systems, which presents a challenge for organizations that still
rely on the language.
- To address this, some institutions are offering COBOL training programs to bring new developers into the field.
2. Modernization
and Integration :
- While COBOL
remains reliable, some organizations are modernizing their systems by
integrating COBOL programs with newer technologies, such as web services, cloud
computing, and mobile apps.
- COBOL modernization projects involve refactoring COBOL code, updating system interfaces, or even re-hosting COBOL applications on modern platforms. Hybrid systems allow companies to maintain their COBOL core while interacting with modern technologies.
3. Attempts to
Replace COBOL :
- Although many organizations are exploring alternatives to COBOL, complete rewrites in modern languages like Java or Python are costly and risky. COBOL's long track record of reliability and the sheer complexity of migrating decades-old systems have made it difficult for companies to phase it out entirely.
COBOL's Continued Importance:
COBOL remains indispensable for large organizations and governments where massive amounts of data need to be processed efficiently and reliably. Many critical systems still rely on COBOL because the risk of replacing or fully re-engineering these systems is too high. While other programming languages may dominate newer software projects, COBOL continues to quietly power the world’s financial systems, government programs, and essential business operations.
In summary, COBOL remains vital because of:
- Its proven stability
and performance .
- The enormous
cost and complexity of replacing legacy systems .
- Its specific
strengths in transaction processing, data management, and reporting .
- Its strong presence on mainframes, which are still used for mission-critical applications .
While COBOL may not be glamorous, it is the backbone
of many essential industries.
=====
Introduction to COBOL
Sections
§ A section is a block of code made up of one or more paragraphs.
§ A section begins with the section name and ends where the next
section name is encountered or where the program text ends.
§ A section name consists of a name devised by the programmer
or defined by the language followed by the word SECTION
followed by a full stop.
Introduction to COBOL
Paragraphs
§ Each section consists of one or more paragraphs.
§ A paragraph is a block of code made up of one or more
sentences.
§ A paragraph begins with the paragraph name and ends with
the next paragraph or section name or the end of the
program text.
§ The paragraph name consists of a name devised by the
programmer or defined by the language followed by a full
stop.
PrintFinalTotals.
PROGRAM-ID.
Introduction to COBOL
Sentences and Statements
§ A paragraph consists of one or more sentences.
§ A sentence consists of one or more statements and is terminated by a full
stop.
MOVE .21 TO VatRate
COMPUTE VatAmount = ProductCost * VatRate.
DISPLAY "Enter name " WITH NO ADVANCING
ACCEPT StudentName
DISPLAY "Name entered was " StudentName.
§ A statement consists of a COBOL verb and an operand or operands.
SUBTRACT Tax FROM GrossPay GIVING NetPay
READ StudentFile
AT END SET EndOfFile TO TRUE
END-READ.
IDENTIFICATION DIVISION.
PROGRAM-ID. SAMPLE1.
AUTHOR. Michael Coughlan.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 Num1 PIC 9 VALUE ZEROS.
01 Num2 PIC 9 VALUE ZEROS.
01 Result PIC 99 VALUE ZEROS.
PROCEDURE DIVISION
CalculateResult.
ACCEPT Num1.
ACCEPT Num2.
MULTIPLY Num1 BY Num2 GIVING Result.
DISPLAY "Result is = ", Result.
STOP RUN
==
The minimum COBOL program
IDENTIFICATION DIVISION.
PROGRAM-ID. SAMPLE2.
PROCEDURE DIVISION.
DisplayPrompt.
DISPLAY "I
==
Almost all COBOL compilers treat a line of COBOL code as if it contained
two distinct areas. These are known as;
Area A and Area B
§ When a COBOL compiler recognizes these two areas, all division, section,
paragraph names, FD entries and 01 level numbers must start in Area A. All
other sentences must start in Area B.
§ Area A is four characters wide and is followed by Area B.
===
Name Construction
All user defined names, such as data names, paragraph names,
section names and mnemonic names, must adhere to the following
rules;
– They must contain at least one character and not more than 30
characters.
– They must contain at least one alphabetic character and they must
not begin or end with a hyphen.
– They must be contructed from the characters A to Z, the number 0 to
9 and the hyphen. e.g. TotalPay, Gross-Pay,
PrintReportHeadings, Customer10-Rec
§ All data-names should describe the data they contain.
§ All paragraph and section names should describe the function of
the paragraph or section.
COBOL Basics 1
N=====
Describing DATA
There are basically three kinds of data used in COBOL programs;
1. Variables.
2. Literals.
3. Figurative Constants.
Unlike other programming languages, COBOL does not support
user defined constants.
====
Data-Names / Variables
A variable is a named location in memory into which a program can put
data and from which it can retrieve data.
§ A data-name or identifier is the name used to identify the area of memory
reserved for the variable.
§ Variables must be described in terms of their type and size.
§ Every variable used in a COBOL program must have a description in the
DATA DIVISION.
While COBOL may
not be seen as a "modern" or "trendy" programming language
like Python, Java, or JavaScript, it plays a crucial role as the backbone of
many essential industries due to its stability, reliability, and efficiency in
handling large-scale business operations. Its ability to process massive
amounts of transactions and data on a daily basis is invaluable in sectors
where accuracy, speed, and uninterrupted service are non-negotiable.
Key Reasons Why COBOL Remains the Backbone of Essential Industries:
1. Stability
and Reliability :
- COBOL has
been used in production for over 60 years, and many of the systems running
today were developed decades ago. These systems continue to operate with
minimal failures, providing consistent
and reliable performance .
- For industries such as banking, insurance, and government, where downtime can lead to massive financial losses or disruptions to essential services, COBOL's reliability is crucial.
2. Handling
Large-Scale Transactions :
- Industries
that deal with millions or even
billions of transactions daily, such as banks processing credit card
payments or payroll systems handling employee salaries, rely on COBOL’s ability
to efficiently process batch data.
- COBOL’s transactional integrity and ability to handle large volumes of data make it the go-to language for applications where accurate record-keeping is critical.
3. Compatibility
with Mainframes :
- Mainframes
are still heavily used by organizations that require massive data processing
power and high availability. COBOL was designed to run on these systems, making
it ideal for companies with established mainframe infrastructures.
- COBOL applications running on mainframes have been fine-tuned over the years, providing an unmatched level of performance and reliability for business-critical operations.
4. Long-Term
Use and Investment :
- Companies
have invested heavily in COBOL systems over the past few decades. These systems
form the core infrastructure of
many businesses and government agencies.
- Replacing COBOL systems with modern software is not just expensive but risky . The sheer complexity of migrating essential systems without causing disruptions to business operations has deterred many organizations from moving away from COBOL entirely.
5. Business-Centric
Features :
- COBOL was
built for business applications , particularly those focused on data processing , reporting , and financial operations . It has built-in support for handling things
like large data files, formatted reports, and precise decimal calculations, all
of which are critical in industries like finance and government.
- Its highly readable, English-like syntax also makes COBOL easy to maintain for professionals in business roles who may not be computer scientists but need to understand how these systems operate.
6. Regulatory
and Compliance Needs :
- In industries
like banking , insurance , and government
, COBOL systems are often closely tied to regulatory compliance . These industries require strict adherence
to rules regarding financial reporting, auditing, and customer data security.
- COBOL’s long-established processes, along with the fact that it’s been optimized over decades for these tasks, make it a trusted choice for managing sensitive, regulated data.
The Glamour of COBOL’s Dependability:
Though COBOL may not be seen as "glamorous" in the way cutting-edge languages and tools are, it serves as a foundation that allows essential industries to operate smoothly. These industries require software that can handle high-volume transactions with impeccable accuracy and reliability. While newer technologies may offer fancy features or faster development times for consumer-facing applications, COBOL remains indispensable for the critical systems that keep the world's financial, government, and business sectors functioning.
Examples of COBOL in Use:
1. Banks : Large banks like JPMorgan Chase, Bank of America, and Wells Fargo still rely on COBOL systems to manage customer accounts, process transactions, and run ATMs. COBOL handles 90% of all ATM transactions globally.
2. Insurance : Companies like MetLife and Prudential run core policy and claims management systems on COBOL.
3. Governments : Government agencies like the U.S. Social Security Administration and IRS use COBOL for managing citizens' financial data, taxes, and benefits. COBOL handles a significant portion of social security and unemployment benefits calculations.
4. Retail : Major retailers use COBOL for inventory management and supply chain logistics , ensuring that products move efficiently from manufacturers to customers.
In Conclusion:
COBOL may not be cutting-edge or flashy, but it
quietly powers the systems that the world depends on every day. Whether it's
processing billions of dollars in transactions or managing essential public
services, COBOL is the unsung hero behind
the scenes, enabling the modern economy to function smoothly. Its longevity and
continued use in critical systems demonstrate that glamour isn’t always about being new —sometimes, it’s about being reliable,
resilient, and indispensable.
======
====
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