About MERN Interview Preparation
🚀🚀 Welcome to our MERN Interview Preparation series! In this series, we will explore topics and questions commonly encountered in real-world interviews. Our goal is to prepare you with the knowledge and skills necessary to confidently tackle MERN-related interview challenges. We'll explore a range of subjects from fundamental concepts to advanced techniques, ensuring you're well-prepared for any question that comes your way. Whether you're a beginner or looking to brush up on your skills, this series will provide valuable insights and practical tips to help you succeed in your MERN interviews. 🚀🚀
JavaScript
- What are Pure Functions in JavaScript?
- What is hoisting in JS?
- How does JavaScript work?
- What is the difference between let, var, and const?
- What is an event loop?
- Difference between Local Storage, Session Storage, and Cookies?
- What are generator functions? to control the flow of execution and create iterable sequences of values?
- What is the difference between setTimeout and setInterval?
- What do you mean by "rest and spread operator"?
- What is meant by Shallow Copy and Deep Copy?
- What are closures?
- What is the difference between a promise and a callback?
- What are arrow functions in JavaScript?
- Explain About ES6 features?
- What is the difference between the ES6 and ES5 standards?
- What is currying in JavaScript?
- What is a temporal dead zone?
- What are Event bubbling and Event Capturing in JavaScript?
- What is a mutation observer?
- Falsy values in JavaScript?
- Object.seal vs Object.freeze?
- Explain Call, Bind, and Apply in JavaScript with examples.
- Explain Higher Order Functions in JavaScript.
- Explain Scope and Scope Chain in JavaScript.
- What are Object Prototypes?
- What are Callbacks?
- What is the difference between PUT, POST, and PATCH?
- What is IIFE in JS explain with an example.
React JS
- What are synthetic events?
- How does React work?
- What is the distinction between client-side and server-side rendering?
- Why use React instead of other frameworks, like Angular, or VueJS?
- What is reconciliation?
- What is the Virtual DOM?
- How to Optimize React App?
- What is React Fiber?
- What are React Portals?
- What is useReducer in React?
- What are Error Boundaries?
- What is Profiler in React JS?
- Why is there a need for using keys in lists?
- What are the differences between controlled and uncontrolled components?
- What is prop drilling in React?
- What are custom hooks? Create a hook.
- Explain Strict Mode in React.
- How do I pass data between Child to Parent react components?
- Difference between a class Component and a Functional Component?
- What are the hooks, you have used?
- What is the purpose of useCallback, useMemo and React.memo, what is the difference?
- Explain Forwarding Refs in React.
- What are Class-based lifecycle methods?
- Difference between Debounce and Throttle, and how to implement?
- How would you be able to achieve componentDidMount, componentDidUpdate, & componentDidUnMount in a functional-based component?
- What are pure components and what is their purpose?
- What are higher-order components?
- What HODs have you used? Write an example.
- Have you used the context API? Explain it.
- We already have state management in React, so why so for Redux?
- How does Redux work?
- Have you used any middleware?
- How to Write Unit Tests in React?
- Explain the CORS error and how to fix it.
- Explain the concept of “lifting up in React”.
- How can we change props in React?
- Is setState() method synchronous or asynchronous?
- How to Handlers Async Events in React?
- What are Async Event Handlers in React?
- Can we setState through the onClick event in React?
- Latest version of React JS, What features in Latest React version?
- What is the difference between Promises and Observables?
- What is formik in react?
- What is Batching in react?
- How to optimize performance in react
Node JS & Express JS
- Create a Hello World app in Node JS.
- Create a Hello World app in Express JS.
- What is Tracing in Node.js?
- What is the Reactor Pattern in Node.js?
- Manage API Version in an Express App
- How To Run Multiple Versions of Node.js with Node Version Manager.
- What is the child process in node js explain?
- What is the cluster in node js?
- What is eventemitter in node js?
- How to upload files in node js API.
- What is the global object in node JS?
- What is the stream in node JS?
- What is the buffer in node JS?
- Explain JWT authentication in Node JS.
- What is an n +1 query?
- What is the Difference between PHP, Node JS, and Python?
- What is the difference between setimmediate, settimeout and process.nexttick?
- What is Unit test case and what is test coverage?
MongoDB
- What is Aggregation in MongoDB explain.
- Explain relationships in MongoDB.
- What is Sharding?
- What is Replication?
- What are the indexing limitations in MongoDB?
- MySQL vs MongoDB explains, which database we need to choose for our application and why
- Explain transactions in MongoDB
- What are ASID properties in MongoDB?
- What is Replication in MongoDB?
- What is sharding in MongoDB?
- How the ObjectId work in MongoDB?
- What is Capped Collection in MongoDB?
Problem Solving
- What is the output? Problem #1
- Have a form loaded with initial data and the submit button is disabled, make it enabled if anything updates in form
- Sort the data according to sortingOrder Problem #3
- Complete the createToggle function Problem #4
Guess the output
- Guess the output #1
- Guess the output #2
- Solve the problem using spread operator #3
- Guess the output #4