Understanding the MERN Stack

What does MERN stand for?

• MySQL, Express.js, React, Node.js

• MongoDB, Express.js, React, Node.js

• MongoDB, Express.js, Vue.js, Node.js

• MongoDB, Django, React, Node.js

What is the primary purpose of MongoDB?

• To provide a relational database solution.

• To serve as a primary key management system.

• The primary purpose of MongoDB is to provide a scalable and flexible database solution for handling large amounts of data.

• To act as a file storage system.

How do you define a route in Express.js?

• A route in Express.js is defined using app.get(path, handler).

• A route in Express.js is defined using app.METHOD(path, callback).

• A route in Express.js is defined using app.use(path, middleware).

• A route in Express.js is defined using app.route(path, callback).

What is a functional component in React.js?

• A functional component is a built-in React library for styling.

• A functional component is a type of React hook.

• A functional component is a JavaScript function that returns a React element and can accept props.

• A functional component is a class that manages its own state.

How do you set up a basic Node.js server?

• Run 'npm install express' instead of Node.js.

• 1. Install Node.js. 2. Create a file (e.g., server.js). 3. Write 'const http = require("http");' 4. Create server: 'const server = http.createServer((req, res) => { res.writeHead(200, { 'Content-Type': 'text/plain' }); res.end('Hello World!'); });' 5. Listen on a port: 'server.listen(3000, () => { console.log('Server running at http://localhost:3000/'); });'

• Use 'const server = require("express")();' to create the server.

• Create a file named 'index.html' for the server.

What is the role of Mongoose in a MERN application?

• Mongoose is a library for managing user authentication in a MERN application.

• Mongoose is a SQL database used for data storage in a MERN application.

• Mongoose serves as an ODM for MongoDB in a MERN application, facilitating data modeling and database interactions.

• Mongoose is a front-end framework for React in a MERN application.

How can you pass props to a React component?

• Props can only be passed through Redux.

• You pass props to a React component by using attributes in the component's JSX tag.

• You pass props by defining them in the component's state.

• You cannot pass props to functional components.

What middleware is commonly used in Express.js for parsing JSON?

• jsonParser()

• express.urlencoded()

• bodyParser.json()

• express.json()

What command is used to create a new React app?

• create-react-app new-app

• npm init react-app my-app

• npx create-react-app my-app

• yarn create react-app my-app

How do you handle asynchronous operations in Node.js?

• Use synchronous functions exclusively.

• Ignore error handling in callbacks.

• Use global variables for state management.

• Use callbacks, Promises, or async/await to handle asynchronous operations in Node.js.