Grok all the things

grok (v): to understand (something) intuitively.

COBOL

🙇‍♀️  Students & Apprentices

Ah, COBOL! That vintage programming language that still manages to stand tall amidst modern tech giants like Java, Python, and JavaScript! If you've ever heard of COBOL and wondered what all the fuss is about, buckle up and join me on this delightful journey through the fascinating world of COBOL. We'll explore its history, use cases, and even dive into some code samples—trust me, you won't be disappointed!

🌍 A Brief History of COBOL: Birth of a Legend

COBOL, which stands for "COmmon Business-Oriented Language," first saw the light of day back in 1959. Grace Hopper, a Rear Admiral in the US Navy and a computer programming pioneer, was one of the key people behind its creation. The idea was simple: create a portable and easy-to-understand language for business applications. And guess what? COBOL delivered on that promise!

Over the years, this marvelous language has gone through many revisions and updates, with the most recent version being COBOL 2014. Despite all these changes, COBOL has managed to maintain its core values of readability, simplicity, and efficiency.

🏢 COBOL: Still Standing Strong in the Business World

You might be thinking, "Well, it's an old language. Can it still be relevant today?" Brace yourself for a shocker: COBOL is alive and kicking! In fact, it's still widely used in core banking, finance, insurance, and government systems—handling transactions worth trillions of dollars every day! Talk about incredible staying power!

One of the reasons for COBOL's longevity is its unparalleled stability and reliability. When dealing with business-critical applications, these are features that never go out of style.

📝 Time to Grok COBOL: Writing Your First Program

Now that we've seen the big picture, let's dive into the nitty-gritty of COBOL programming. Get ready to grok COBOL through some hands-on examples!

🔣 COBOL Syntax and Structure

COBOL programs have a distinctive hierarchical structure divided into four divisions:

  1. Identification Division
  2. Environment Division
  3. Data Division
  4. Procedure Division

Each division is made up of sections, and sections are further divided into paragraphs. COBOL's syntax is designed to resemble plain English, making it easy to read and understand once you get the hang of it.

🖋️ Writing a Simple "Hello, World!" Program in COBOL

Ready to write some COBOL code? Let's start with the classic "Hello, World!" example:

IDENTIFICATION DIVISION.
PROGRAM-ID. HelloWorld.

ENVIRONMENT DIVISION.

DATA DIVISION.

PROCEDURE DIVISION.
    DISPLAY "Hello, World!".
    STOP RUN.

Here's what each line does:

  • IDENTIFICATION DIVISION.: Defines the beginning of the program.
  • PROGRAM-ID. HelloWorld.: Gives the program a name—HelloWorld in this case.
  • ENVIRONMENT DIVISION.: Typically used to specify file organization and system configuration, but not needed for our simple example.
  • DATA DIVISION.: Used to declare data items and variables, also not needed here.
  • PROCEDURE DIVISION.: The main action happens here! This is where our executable code goes.
  • DISPLAY "Hello, World!".: Displays the text "Hello, World!" on the screen.
  • STOP RUN.: Ends the program execution.

Not too bad, right? COBOL code is verbose but super readable!

🧮 A COBOL Program to Add Two Numbers

Let's take it up a notch and create a COBOL program to add two numbers:

IDENTIFICATION DIVISION.
PROGRAM-ID. AddTwoNumbers.

ENVIRONMENT DIVISION.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 NUM-A       PIC 9(3) VALUE 0.
01 NUM-B       PIC 9(3) VALUE 0.
01 SUM         PIC 9(4) VALUE 0.

PROCEDURE DIVISION.
    ACCEPT NUM-A.
    ACCEPT NUM-B.

    ADD NUM-A, NUM-B GIVING SUM.

    DISPLAY "The sum of " NUM-A " and " NUM-B " is " SUM ".".

    STOP RUN.

In this example, we've added a WORKING-STORAGE SECTION within the DATA DIVISION. This is where we declare our variables:

  • 01 NUM-A PIC 9(3) VALUE 0.: Declares a numeric variable NUM-A with a maximum length of 3 digits and initializes it to 0.
  • 01 NUM-B PIC 9(3) VALUE 0.: Same as NUM-A, but for NUM-B.
  • 01 SUM PIC 9(4) VALUE 0.: Declares a numeric variable SUM with a maximum length of 4 digits and initializes it to 0.

In the PROCEDURE DIVISION, we:

  • Accept user input for the two numbers (NUM-A and NUM-B).
  • Perform the addition and store the result in SUM.
  • Display the result on the screen.
  • Finish the program execution with STOP RUN.

That's it! COBOL, once mastered, can be a powerful and efficient tool for business-oriented tasks.

📖 A COBOL Adventure: Explore the Future! 🚀

While COBOL may be an old language, it has aged like a fine wine. Today, numerous modern tools and resources are available to make COBOL development smoother. For instance, there are full-fledged COBOL IDEs, plug-ins for popular editors like Visual Studio Code, and even COBOL compilers that run on platforms like .NET and Java. Quite amazing, isn't it?

As you embark on your journey to grok COBOL, remember that you're not just learning a new skill—you're becoming part of an illustrious programming tradition that dates back to the dawn of the computer era. Happy coding, and let the COBOL spirit never die!

Grok.foo is a collection of articles on a variety of technology and programming articles assembled by James Padolsey. Enjoy! And please share! And if you feel like you can donate here so I can create more free content for you.