Node.js Tutorial
Subject: Node.js
What is Node.js?
Node.js is an open-source, cross-platform runtime environment that lets you run JavaScript on the server. It's built on Google Chrome's V8 engine, making it fast and efficient for building scalable web applications, APIs, and real-time tools.
Why Use Node.js?
Runs JavaScript on the Server
Node.js enables developers to write both frontend and backend code in JavaScript.
High Performance
Uses the V8 engine to compile JavaScript to machine code for fast execution.
Asynchronous and Event-Driven
Node.js uses non-blocking I/O and an event loop to handle concurrent requests.
Single-Threaded but Scalable
Although it runs on a single thread, the event loop allows it to scale for large applications.
Large npm Ecosystem
The Node Package Manager (npm) gives access to thousands of open-source libraries and tools.
Installing Node.js
- Go to https://nodejs.org
- Download and install the LTS version.
- Verify installation:
Output:
Writing Your First Node.js Program
hello.js
Run Command:
Output:
Creating a Basic HTTP Server
server.js
Run Command:
Terminal Output:
Browser Output:
Initializing a Node.js Project
Creates a package.json file for tracking dependencies and project metadata.
Installing External Modules
Installs Express.js and updates package.json and node_modules/.
Key Takeaways
- Node.js runs JavaScript on the server-side.
- Built on Chrome's V8 engine for performance.
- Uses non-blocking, event-driven architecture.
- Ideal for building web servers, APIs, and real-time apps.
- Has built-in modules and a huge package ecosystem via npm.