This repository aims to compile a collection of the most commonly asked interview questions. We invite you to contribute by sharing your interview experiences and questions encountered. Feel free to submit a pull request (PR) with your contributions in the appropriate section.
- What is JavaScript, and what are its key features?
- Explain the difference between
==
and===
in JavaScript. - What is the difference between
let
,const
, andvar
in JavaScript? When would you use each? - What is closure in JavaScript? Provide an example.
- How does prototypal inheritance work in JavaScript?
- What are the different data types in JavaScript?
- Describe event bubbling and event capturing in JavaScript.
- Explain the difference between
null
andundefined
in JavaScript. - What are the different ways to declare variables in JavaScript?
- How does Asynchronous JavaScript work, and what are the different techniques to handle it?
- What is the purpose of the
this
keyword in JavaScript? How is its value determined? - Explain the concept of hoisting in JavaScript.
- What are arrow functions in JavaScript? How do they differ from regular functions?
- What is the purpose of the
Promise
object in JavaScript? How do you use it? - How does the
async/await
syntax work in JavaScript? How does it improve asynchronous code readability? - What are the key differences between
map
,filter
, andreduce
in JavaScript? Provide examples of each. - Explain the concept of scope in JavaScript. How does lexical scoping work?
- What is a callback function in JavaScript? Provide an example of how you would use one.
- What are the different ways to handle errors in JavaScript?
- Describe the concept of a higher-order function in JavaScript. Provide an example.
- What is the difference between synchronous and asynchronous code execution in JavaScript?
- Describe the difference between the
for...in
loop and thefor...of
loop in JavaScript. - Explain the difference between
map
andforEach
in JavaScript. - What are the differences between
splice
andslice
in JavaScript? Provide examples of each.
- What is React, and what are its key features?
- Why do some developers prefer React over Angular and Vue.js?
- Give the two most significant drawbacks of React.
- Explain the difference between class components and functional components in React.
- What is JSX, and why is it used in React?
- What are React Fragments, and why are they used?
- What are the lifecycle methods in React, and how do they work?
- What is state in React, and how is it managed?
- Describe the concept of virtual DOM in React.
- What is Babel in React js ?
- What are React Hooks, and how do they differ from class-based components?
- How does React Router work, and what are its key components?
- Describe the concept of context in React. How is it used to pass data through the component tree?
- What are controlled components in React? Provide an example.
- What are the main difference between Pros and State ?
- What are React Hooks, and how do they differ from class-based components?
- Explain the concept of Higher Order Components (HOCs) in React.
- Describe the concept of context in React. How is it used to pass data through the component tree?
- What is the Flux architecture, and how does it differ from traditional MVC?
- What is Redux, and how does it complement React?
- How does Redux handle state management in a React application?
- What is the 'Store' feature in Redux, and how does it manage application state?
- Explain the role of the dispatcher in Redux and how it facilitates the flow of actions to reducers.
- How do you optimize performance in a React application?
- What are the main features of Java programming language?
- Explain the difference between
==
and.equals()
in Java. - What are the access modifiers in Java, and what do they mean?
- What is the difference between
ArrayList
andLinkedList
in Java? - What is method overloading and method overriding in Java?
- How does exception handling work in Java? Provide an example.
- What is the difference between
final
,finally
, andfinalize
in Java? - Explain the concept of multithreading in Java.
- What are the different types of inheritance in Java?
- What is the purpose of the
static
keyword in Java?
- What is the difference between HTTP and HTTPS?
- Explain the concept of CORS (Cross-Origin Resource Sharing) in web development.
- How do you ensure your website is accessible to users with disabilities?
- What is the box model in CSS, and how does it work?
- Describe the difference between inline, block, and inline-block elements in CSS.
- What are media queries in CSS, and how are they used for responsive web design?
- What is the purpose of the
viewport
meta tag in HTML? - How do you optimize website performance and loading speed?
- Explain the difference between cookies, local storage, and session storage in web development.
- What are the advantages and disadvantages of using CSS preprocessors like Sass or Less?
- Describe the differences between client-side scripting and server-side scripting in web development.
- Explain the purpose of a content delivery network (CDN) and how it improves website performance.
- What are the benefits of using responsive web design principles in modern web development?
- Describe the process of optimizing a website for search engines (SEO).
- How do you ensure your website is secure from common vulnerabilities such as cross-site scripting (XSS) and SQL injection?
- What are some best practices for designing and developing a mobile-first website?
- How do you approach optimizing images and multimedia content for the web?
- Describe the importance of web standards and how they impact web development.
- How would you implement lazy loading of images on a website to improve performance?
- Can you explain the concept of progressive web apps (PWAs) and their benefits over traditional web apps?
- What is the difference between frontend and backend development?
- Explain the MVC (Model-View-Controller) architecture pattern.
- Describe the role of databases in backend development, and list some popular database systems.
- What is RESTful API, and how does it work?
- Explain the difference between stateful and stateless communication in backend systems.
- What is authentication and authorization in backend development? How are they implemented?
- Describe the concept of middleware in backend frameworks like Express.js.
- How does caching work in backend systems, and what are its benefits?
- What are microservices, and how do they differ from monolithic architectures?
- Discuss the importance of security in backend development, and list some common security vulnerabilities and how to mitigate them.