Ques 1. What is Node.js?
Node.js is an open-source, cross-platform JavaScript runtime environment that executes JavaScript code server-side.
Example:
console.log('Hello, Node.js!');
Ques 2. Explain the event-driven architecture in Node.js.
Node.js follows an event-driven, non-blocking I/O model. It means that the server can handle multiple connections simultaneously, and when an event occurs, the corresponding callback function is executed.
Example:
const server = require('http').createServer((req, res) => { /* handle request */ });
Ques 3. What is npm?
npm (Node Package Manager) is the default package manager for Node.js, used to manage and distribute Node.js packages/modules.
Example:
npm install package_name
Ques 4. Explain the concept of middleware in Express.js.
Middleware functions are functions that have access to the request, response, and next middleware function in the application’s request-response cycle. They can modify the request and response objects or end the request-response cycle.
Example:
app.use((req, res, next) => { /* middleware logic */ next(); });
Ques 5. What is the purpose of package.json in Node.js?
package.json is a manifest file that contains metadata about a Node.js project, including dependencies, scripts, and other project-specific configurations.
Example:
npm init