Node.js Basics Guide

What is Node.js?

Node.js is an open-source, cross-platform JavaScript runtime environment that executes JavaScript code outside a web browser. It allows developers to use JavaScript to write command-line tools and server-side scripts.

Key Features

Non-blocking I/O: Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient.
NPM (Node Package Manager): Provides access to a large ecosystem of open-source packages.
Single-threaded but highly scalable: Uses an event loop to handle multiple connections concurrently.

Installation

Install Node.js

Download and install from nodejs.org, or use package managers:

bash

Verify installation:

bash

Creating Your First Node.js Application

Create a directory for your project:

bash

Initialize a new Node.js project:

bash

Create a file named app.js:

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Run your application:

bash

Built-in Modules

Node.js comes with several built-in modules that you can use without installation:

File System (fs)

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HTTP

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Path

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NPM Packages

NPM (Node Package Manager) allows you to install and manage third-party packages.

Installing Packages

bash

Using Packages

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Asynchronous Programming

Node.js is built around asynchronous programming. There are several ways to handle asynchronous operations:

Callbacks

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Promises

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Async/Await

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Event Emitters

Node.js uses an event-driven architecture with many objects that emit events:

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Error Handling

Try-Catch Blocks

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Handling Uncaught Exceptions

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Resources for Further Learning

Debugging Node.js Applications

Using the --inspect flag: node --inspect app.js
Using Visual Studio Code's built-in debugger
Using the debug npm package

Next Steps

Learn Express.js for building web applications
Explore databases like MongoDB or PostgreSQL with Node.js
Study authentication and security in Node.js applications
Learn about RESTful API design principles

node-basics.mdx