Node.js Tutorial for Beginners: Learn Node in 1 Hour

Introduction

This tutorial provides a comprehensive introduction to Node.js, perfect for beginners looking to get started with this powerful JavaScript runtime. In just one hour, you'll learn the basics of Node.js, understand its architecture, and write your first program. This guide is a great stepping stone towards mastering full-stack development.

Step 1: Understand What Node.js Is

• Node.js is a JavaScript runtime built on Chrome's V8 engine.
• It enables the development of fast and scalable server-side applications.
• Key benefits include:
  • Non-blocking I/O for high performance.
  • A single programming language (JavaScript) for both client and server-side code.

Step 2: Explore Node.js Architecture

• Node.js uses an event-driven, non-blocking I/O model.
• Key components of Node.js architecture include:
  • Event Loop: Handles asynchronous operations.
  • Event Emitter: Allows objects to communicate with each other.
  • Callback Functions: Functions passed as arguments to handle events.

Step 3: Learn How Node.js Works

• Node.js operates on a single-threaded event loop.
• It can handle multiple connections simultaneously without blocking the execution of code.
• This architecture makes it suitable for I/O-heavy applications.

Step 4: Install Node.js

• Download the Node.js installer for your operating system from the official website.
• Follow the installation instructions specific to your OS.
• Verify the installation by running the following commands in your terminal:

  node -v
  npm -v
  

Step 5: Write Your First Node.js Program

• Create a new file named app.js.
• Add the following code to display a message:

  console.log("Hello, Node.js!");
  

• Run the program using the command:

  node app.js
  

Step 6: Understand the Node Module System

• Node.js uses a module system to organize code into reusable components.
• Each file in a Node.js application is treated as a module.
• Common modules include:
  • HTTP Module: For creating web servers.
  • File System Module: For interacting with the file system.

Step 7: Work with the Global Object

• The global object in Node.js is similar to the window object in browsers.
• It provides access to various global properties and methods.
• Use global to access global variables from any module.

Step 8: Create and Load a Module

• To create a module, define your functions in a separate file, e.g., myModule.js:

  function greet() {
      console.log("Hello from my module!");
  }
  
  module.exports = greet;
  

• Load the module in your main file:

  const greet = require('./myModule');
  greet();
  

Step 9: Understand the Module Wrapper Function

• Every module in Node.js is wrapped in a function to create a private scope.
• This prevents variables from polluting the global scope.
• Use exports and module.exports to expose functions or objects outside the module.

Step 10: Explore Built-in Modules

• Familiarize yourself with commonly used built-in modules:
  • Path Module: Helps with file and directory path manipulation.
  • OS Module: Provides information about the operating system.
  • File System Module: Allows reading and writing files.
  • Events Module: Provides event-driven programming capabilities.

Step 11: Use the HTTP Module

• Create a simple web server using the HTTP module:

  const http = require('http');
  
  const server = http.createServer((req, res) => {
      res.statusCode = 200;
      res.setHeader('Content-Type', 'text/plain');
      res.end('Hello, World!\n');
  });
  
  server.listen(3000, () => {
      console.log('Server running at http://localhost:3000/');
  });
  

• Run the server and access it through your web browser.

Conclusion

In this tutorial, you learned the fundamentals of Node.js, including its architecture, module system, and how to create a simple web server. This knowledge forms the foundation for building more complex applications. As a next step, consider exploring additional Node.js features and frameworks to enhance your skills further. Happy coding!