Pascal, a procedural high-level programming language, holds a special place in the history of computer science, particularly for teaching coding to generations of children during the 70s and 80s. Created by the Swiss computer scientist Niklaus Wirth in the late 1960s, this language was named in honor of the renowned French mathematician Blaise Pascal. Its foundation was laid upon the ALGOL 60 language, but it quickly evolved to incorporate more advanced data structuring capabilities, enabling developers to build dynamic recursive data structures like trees and graphs.

The Rise of Pascal

Pascal gained widespread popularity when it became the programming language of choice for early personal computers, starting with the Apple II and later the Lisa and Macintosh. Its influence extended as it became the default high-level language on nearly every PC by the mid-1980s. Over the years, various dialects of Pascal emerged, one of the most notable being Turbo Pascal, developed by Anders Hejlsberg. • Turbo Pascal was one of the first languages to offer a full-screen Integrated Development Environment (IDE), making it user-friendly and accessible.

In 1983, Turbo Pascal could be purchased at Circuit City for just $49.99 – a fantastic deal at that time. The language was not only used as a learning tool in educational settings but also contributed to the development of serious desktop applications and games like “Crisis Mountain,” “Gravity Wars,” and IBM’s “Alley Cat.”

Modern Usage and Relevance

While the popularity of Pascal has declined over the years, various Pascal dialects, such as Delphi, continue to be used today. Many programmers find Pascal’s syntax surprisingly familiar, especially those with backgrounds in modern languages like TypeScript.

Getting Started with Pascal

To dive into programming with Pascal, follow these essential steps:

1. Install a Compiler: A good starting point is the Free Pascal Compiler (FPC), which is readily available for free.
2. Create a File: Write your code in a file that ends with the .pas extension. You can also opt for a dedicated IDE like Lazarus, which provides a more robust interface for coding.

Basic Syntax and Structure

To begin your programming journey, we’ll define the main entry point of your application using the program keyword. The structure follows with begin and end, ending with a period, which will execute the actual code within the program—similar to the main function in other languages.

Here’s how you might write your first program to display “Hello, World!”:

program HelloWorld;
begin
  WriteLn('Hello, World!');
end.

Pascal is strictly a procedural language, meaning instructions are executed sequentially, one after the other. The const keyword is employed to define immutable global data, while var indicates variables that may change during program execution. Notably, variables in Pascal are strongly typed with a syntax akin to TypeScript.

Functions and Procedures

The organization of your main program can be achieved using subprograms, which include functions and procedures. A quick distinction between these two:

• Functions: Return a value and are defined with the function keyword, ending with a semicolon.
• Procedures: Do not return a value and are defined with the procedure keyword, also ending with a semicolon.

For example, a simple function could look like this:

function IsOdd(num: Integer): Boolean;
begin
  Result := num mod 2 <> 0;
end;

This function checks if a number is odd and returns a Boolean value. You can call it from your main program to determine the oddity of any integer.

Data Structuring in Pascal

Pascal excels at creating complex data structures. You can create a custom type for a record, analogous to a key-value pair or a dictionary in other programming languages:

type
  Person = record
    Name: string;
    Age: Integer;
  end;
var
  John: Person;
begin
  John.Name := 'John Doe';
  John.Age := 30;
end.

With this example, you can create records in Pascal and access their fields using the dot notation.

Compiling Your Program

Once your code is complete, you can easily build the executable with the compiler, allowing you to run your newly-created Pascal application.

Conclusion

In just a short span, you’ve been introduced to the basics of the Pascal programming language, its historical significance, and how you can start coding with it today. While newer technologies have emerged, Pascal remains a foundational language for learning programming concepts and can be surprisingly relevant in modern development.

If you’re interested in expanding your programming skills or exploring new languages, consider giving Pascal a try! Whether you’re a novice looking to learn the basics or an experienced developer wishing to revisit the foundations, Pascal offers a straightforward yet powerful coding experience.

Explore more about programming languages and enhance your coding journey today!