Express.js

Explain the difference between app.get() and app.use() in Express.js routing.

• app.get() is for handling PUT requests, app.use() is for middleware functions

• app.get() is for middleware functions, app.use() is for handling GET requests

• app.get() is for handling GET requests, app.use() is for middleware functions

• app.get() is for handling POST requests, app.use() is for middleware functions

What is the role of error handling middleware in Express.js?

• Error handling middleware is responsible for database connections in Express.js.

• Error handling middleware is used for routing in Express.js.

• Error handling middleware generates errors intentionally in Express.js.

• Error handling middleware catches errors and handles them during the request-response cycle in Express.js.

What are the advantages of using JWT for authentication in Express.js?

• Difficult to decode

• Large token size

• Stateful authentication

• Stateless authentication, compact, self-contained, easily verifiable, custom claims

How can you connect Express.js with MongoDB?

• Use the Sequelize library to connect Express.js with MongoDB.

• Manually write custom code to establish a connection between Express.js and MongoDB.

• Use the mongoose library to connect Express.js with MongoDB.

• Use the SQLite database instead of MongoDB to connect with Express.js.

What is Mongoose and how is it used in Express.js for database operations?

• Mongoose is an ODM library for MongoDB used in Express.js for database operations.

• Mongoose is a front-end framework for Express.js

• Mongoose is a SQL database management system

• Mongoose is used in Express.js for styling web pages

What is the purpose of async/await in database operations in Express.js?

• To improve the performance of database operations

• To convert synchronous database operations to asynchronous

• To handle database operations in a parallel manner

• To handle asynchronous database operations in a synchronous manner.

How can you handle database queries in a synchronous manner in Express.js?

• Use synchronous database libraries like SQLite or synchronous functions provided by the database library.

• Implement a custom synchronous database handler in Express.js

• Use asynchronous database libraries like SQLite

• Use setTimeout() to delay the execution of queries

What are the common security vulnerabilities in Express.js applications?

• XSS, CSRF, NoSQL Injection

• XSS, SQL Injection, CSRF, NoSQL Injection

• XSS, SQL Injection, NoSQL Injection

• XSS, SQL Injection

How can you prevent SQL injection attacks in Express.js?

• Trust all user input without sanitization

• Use parameterized queries or ORM libraries like Sequelize or Knex.js

• Ignore input validation and directly execute user queries

• Use plain text queries without any validation

What are the best practices for securing user sessions in Express.js?

• Ignore expiration times

• Share session tokens across users

• Use secure cookies, implement CSRF protection, use session tokens, set proper expiration times, and rotate session tokens.

• Use weak cookies