An Online Pascal Compiler is a web-based platform That allows users to write, edit, debug, execute and share code directly in their browser without local installations. It offers real-time code execution, syntax highlighting, and error debugging, and supports multiple Pascal versions, enhancing accessibility and productivity. Pascal compilers offers an integrated development environment (IDE) that includes features like syntax highlighting, error checking, code completion, and the ability to see the code output in real time.

About Pascal

Pascal is a high-level programming language developed in the late 1960s by Niklaus Wirth. Named after the renowned French mathematician Blaise Pascal, the language was initially designed for teaching programming and good software engineering practices.

Pascal is statically typed and known for its simplicity, clarity, and efficiency. It encourages structured programming and data structuring through its use of subroutines, blocks, and record data types, making it easier to understand and debug.

It was widely used in the 1980s and 1990s in education and for commercial software production. The language served as a basis for several other programming languages, including Delphi and Object Pascal, used in modern software development.

While its popularity has waned in the face of languages like Python and Java, Pascal's influence is undeniable, particularly its emphasis on readability and the structured approach to programming. It remains a solid choice for understanding fundamental programming concepts.

Features of Online Pascal compiler

  • It can be accessed through any web browser
  • Easy to use interface and supports various libraries.
  • The syntax highlighting feature colours the elements of the code to increase readability.
  • Compiler’s Autocompletion feature accelerates coding by predicting already defined variables/functions and completing code.

Syntax Help

If-Else Statement: 

if condition then
  {code to be executed if condition is true}
  {code to be executed if condition is false}

Switch Statement:

case expression of
  value1 : begin
    {code to be executed if expression equals value1}
  value2 : begin
    {code to be executed if expression equals value2}
  else begin
    {code to be executed if expression doesn't match any value}

For Loop:

for variable := start to stop do
  {code to be executed for each iteration}

While Loop:

while condition do
  {code to be executed as long as condition is true}

Do-While Loop:

Pascal doesn't have a built-in do-while loop, but you can construct one using a repeat loop and an if statement to create a similar effect:

  {code to be executed}
until not condition;

This code will execute the block at least once and then keep repeating until the condition is false.

Functions in Pascal Compiler

How to declare Function

​​In Pascal, a function is declared in the interface section of a unit or before the begin keyword in a program or procedure. Here's the basic syntax:

function functionName(parameters: dataType): returnType;

For example, a function to add two integers might be declared as follows:

function add(a, b: integer): integer;

How to call Function

To call a function in Pascal, you simply use the function name followed by parentheses containing any arguments that the function may require:

result := add(5, 10);

In this example, the add function is called with 5 and 10 as the arguments, and the result is assigned to the result variable.

How to define Function

The function is defined by providing the block of code that it executes. This block of code is placed after the declaration, using the following syntax:

function functionName(parameters: dataType): returnType;
  { Function body }

For example, the add function might be defined as follows:

function add(a, b: integer): integer;
  add := a + b;

Note that the result of the function is passed back using the assignment operator (:=) with the function name on the left.

Working of the Online Pascal compiler (IDE)

An Online Pascal Compiler is a powerful tool that offers an integrated development environment (IDE) for Pascal programming, all accessible via a web browser. By leveraging cloud technology, it enables users to write, compile, execute, and debug Pascal code in real-time without having to worry about installing any software or maintaining a development environment locally.

The Online Pascal Compiler provides a user-friendly interface with features such as syntax highlighting and code formatting, which greatly improve readability and assist in writing error-free code. Syntax errors are flagged in real-time, providing immediate feedback and making the debugging process smoother and more efficient.

It's equipped with a comprehensive suite of standard Pascal libraries, eliminating the need for manual installations and configurations. The compiler supports multiple Pascal versions, ensuring compatibility with different versions of the language.

The instant 'Run' feature allows developers to execute their Pascal scripts quickly and view the output or any error messages in a dedicated output console. This real-time code execution aids in iterative testing and validation.

The Online Pascal Compiler also offers a platform for collaborative coding, allowing multiple users to work on the same script concurrently. Saved code snippets can be shared with others, fostering learning and collaboration. 

Additionally, being a cloud-based solution, the Online Pascal Compiler ensures that your projects are accessible from any device connected to the internet. The convenience, flexibility, and robust feature set of the Online Pascal Compiler make it a highly effective tool for both learning and professional development in Pascal.

How to write and run the Pascal program online

Writing and running a Pascal program online using an Online Pascal Compiler is a fairly straightforward process. Here is a step-by-step guide:

Step 1: Choose an Online Pascal Compiler

Firstly, decide on an online Pascal compiler that suits your needs. Some popular choices include JDoodle,, and TutorialsPoint's CodingGround. Open the compiler's website in your internet browser.

Step 2: Write Your Pascal Program

Once you have the compiler open, you should see an area where you can input your code. This is where you'll write your Pascal program. For instance, a basic "Hello, World!" program in Pascal would look like this:

program HelloWorld;
  writeln('Hello, World!');

Step 3: Run Your Pascal Program

After your code is written, you can run it by pressing the 'Run', 'Execute', or similarly named button, which is usually located somewhere around the code input area.

Step 4: View Your Output

When you run your program, the output will be displayed in a separate section of the compiler's website. This is typically located to the right or below the code input area.

Step 5: Debugging

If your program has any errors, the compiler will typically highlight these in the code editor or provide an error message in the output section. Use these messages to help debug and correct your code.

Step 6: Save and Share (Optional)

Most online Pascal compilers offer the option to save your work or share it with others. If you want to do this, look for the 'Save', 'Share', or similar button on the webpage.

This guide should help you get started with writing and running Pascal programs online. However, the specific steps might vary a bit depending on the exact online compiler you're using.

Benefits of using Online Pascal compiler

  1. Convenience and Portability: As they're web-based, Online Pascal Compilers can be accessed from any device with an internet connection. You can program from anywhere, at any time.
  2. No Installation Required: No need for software downloads or installations, avoiding potential setup complications and saving disk space.
  3. Real-time Feedback: These compilers offer instant feedback by highlighting syntax errors and providing debugging tools, which aids in learning and increases productivity.
  4. Support for Multiple Pascal Versions: They often support different versions of Pascal, helping you to test code's compatibility across different language versions.
  5. Collaboration and Sharing: Some online compilers allow you to easily share your code with others, fostering collaborative programming or allowing you to showcase your work.
  6. Integrated Development Environment: Online Pascal Compilers often provide a feature-rich interface, including text editors, output consoles, and debugging tools, making coding more streamlined.

Applications of Online Pascal compiler

  1. Education and Learning: The Online Pascal Compiler is a valuable tool for students learning the Pascal language, as it provides immediate feedback and debugging help, aiding in understanding and correcting mistakes.
  2. Software Prototyping: It is useful for quick prototyping and running small chunks of Pascal code to validate logic or learn language features without setting up a local development environment.
  3. Collaborative Development: The Online Pascal Compiler facilitates collaborative development as multiple programmers can work on the same code, making it a useful tool for team projects.
  4. Cross-Platform Development: Being web-based, it supports cross-platform development. Developers can write Pascal code from any device, be it Windows, macOS, or Linux.
  5. Online Assessment: Many educational institutions and employers use online compilers for conducting coding assessments and interviews. It's an efficient way to evaluate a candidate's coding abilities remotely.
  6. Online Code Sharing and Storage: The Online Pascal Compiler allows you to store and share your code online. This is especially useful for tutorials, blogs, or sharing solutions on forums.


This online Pascal compiler is provided for educational and non-commercial use only. While Code 360 works diligently to make it accurate and user-friendly, we cannot guarantee error-free coding as challenges can occasionally arise with this tool. Code 360 is not responsible for any errors in the outcome based on the input by the user resulting from the use of this compiler.