Centum Learning Interview Questions and Answers

Node.js has several core modules that provide essential functionality for building applications.

• HTTP: Allows Node.js to transfer data over the Hyper Text Transfer Protocol (HTTP)

• FS: Provides file system operations like reading and writing files

• OS: Gives information about the operating system on which Node.js is running

• Path: Helps in working with file and directory paths

• Events: Allows to handle events in Node.js applications

process.nextTick() is called before any I/O events, while setImmediate() is called after I/O events.

• process.nextTick() is called at the end of the current event loop cycle, before any I/O events.

• setImmediate() is called at the beginning of the next event loop cycle, after I/O events.

• Use process.nextTick() for executing code asynchronously but as soon as possible.

• Use setImmediate() for executing code asynchronously after I/O events have been processed.

Async in Node.js can be implemented using callbacks, promises, or async/await.

• Use callbacks to handle asynchronous operations in Node.js

• Promises can be used for cleaner asynchronous code

• Async/await provides a more synchronous way to write asynchronous code

Angular is a front-end framework for building client-side applications, while Node.js is a back-end runtime environment for running server-side applications.

• Angular is used for building dynamic web applications with HTML, CSS, and TypeScript.

• Node.js is used for server-side scripting and building scalable network applications.

• Angular is a front-end framework developed and maintained by Google.

• Node.js is a back-end runtime environment that uses JavaScript on the server side.

• Ang...read more

Casendra CQL is a query language used for general operations in Casendra database.

• Casendra CQL is similar to SQL but optimized for Cassandra database

• It supports CRUD operations (Create, Read, Update, Delete)

• It allows for filtering, sorting, and aggregating data

• Example: SELECT * FROM table_name WHERE column_name = value;

Column family is a data model used in NoSQL databases to store related data together.

• Used in NoSQL databases like Apache Cassandra

• Consists of rows and columns

• Columns are grouped together and stored on disk sequentially

• Supports wide rows and dynamic columns

• Example: In a social media application, a column family could store user profiles with columns for name, age, and location