- What is the difference between setState and replaceState methods?
- How to listen to state changes?
- What is the recommended approach of removing an array element in react state?
- Is it possible to use React without rendering HTML?
- How to pretty print JSON with React?
- Why you can't update props in React?
- How to focus an input element on page load?
- What are the possible ways of updating objects in state?
- How can we find the version of React at runtime in the browser?
- What are the approaches to include polyfills in your create-react-app?
- How to use https instead of http in create-react-app?
- How to avoid using relative path imports in create-react-app?
- How to add Google Analytics for react-router?
- How to update a component every second?
- How do you apply vendor prefixes to inline styles in React?
- How to import and export components using react and ES6?
- What are the exceptions on React component naming?
- Why is a component constructor called only once?
- How to define constants in React?
- How to programmatically trigger click event in React?
- Is it possible to use async/await in plain React?
- What are the common folder structures for React?
- What are the popular packages for animation?
- What is the benefit of styles modules?
- What are the popular React-specific linters?
- How to make AJAX call and In which component lifecycle methods should I make an AJAX call?
- What are render props?
React Router
- What is React Router?
- How React Router is different from history library?
- What are the components of React Router v4?
- What is the purpose of push and replace methods of history?
- How do you programmatically navigate using React router v4?
- How to get query parameters in React Router v4
- Why you get "Router may have only one child element" warning?
- How to pass params to history.push method in React Router v4?
- How to implement default or NotFound page?
- How to get history on React Router v4?
- How to perform automatic redirect after login?
React Internationalization
- What is React-Intl?
- What are the main features of React Intl?
- What are the two ways of formatting in React Intl?
- How to use FormattedMessage as placeholder using React Intl?
- How to access current locale with React Intl
- How to format date using React Intl?
React Testing
- What is Shallow Renderer in React testing?
- What is TestRenderer package in React?
- What is the purpose of ReactTestUtils package?
- What is Jest?
- What are the advantages of Jest over Jasmine?
- Give a simple example of Jest test case
React Redux
- What is Flux?
- What is Redux?
- What are the core principles of Redux?
- What are the downsides of Redux compared to Flux?
- What is the difference between mapStateToProps() and mapDispatchToProps()?
- Can I dispatch an action in reducer?
- How to access Redux store outside a component?
- What are the drawbacks of MVW pattern
- Are there any similarities between Redux and RxJS?
- How to dispatch an action on load?
- How to use connect from React Redux?
- How to reset state in Redux?
- What's the purpose of at symbol in the redux connect decorator?
- What is the difference between React context and React Redux?
- Why are Redux state functions called reducers?
- How to make AJAX request in Redux?
- Should I keep all component's state in Redux store?
- What is the proper way to access Redux store?
- What is the difference between component and container in React Redux?
- What is the purpose of the constants in Redux?
- What are the different ways to write mapDispatchToProps()?
- What is the use of the ownProps parameter in mapStateToProps() and mapDispatchToProps()?
- How to structure Redux top level directories?
- What is redux-saga?
- What is the mental model of redux-saga?
- What are the differences between call and put in redux-saga
- What is Redux Thunk?
- What are the differences between redux-saga and redux-thunk
- What is Redux DevTools?
- What are the features of Redux DevTools?
- What are Redux selectors and Why to use them?
- What is Redux Form?
- What are the main features of Redux Form?
- How to add multiple middlewares to Redux?
- How to set initial state in Redux?
- How Relay is different from Redux?
- What is an action in Redux?
Miscellaneous
- What are the main features of reselect library?
- Give an example of reselect usage?
- Does the statics object work with ES6 classes in React?
- Can Redux only be used with React?
- Do you need to have a particular build tool to use Redux?
- How Redux Form initialValues get updated from state?
- How React PropTypes allow different type for one prop?
- Can I import an SVG file as react component?
- Why are inline ref callbacks or functions not recommended?
- What is render hijacking in React?
- What are HOC factory implementations?
- How to pass numbers to React component?
- Do I need to keep all my state into Redux? Should I ever use react internal state?
- What is the purpose of registerServiceWorker in React?
- What is React memo function?
- What is React lazy function?
- How to prevent unnecessary updates using setState?
- How do you render Array, Strings and Numbers in React 16 Version?
- How to use class field declarations syntax in React classes?
- What are hooks?
- What rules need to be followed for hooks?
- How to ensure hooks followed the rules in your project?
- What are the differences between Flux and Redux?
- What are the benefits of React Router V4?
- Can you describe about componentDidCatch lifecycle method signature?
- In which scenarios error boundaries do not catch errors?
- Why do you not need error boundaries for event handlers?
- What is the difference between try catch block and error boundaries?
- What is the behavior of uncaught errors in react 16?
- What is the proper placement for error boundaries?
- What is the benefit of component stack trace from error boundary?
- What is the required method to be defined for a class component?
- What are the possible return types of render method?
- What is the main purpose of constructor?
- Is it mandatory to define constructor for React component?
- What are default props?
- Why should not call setState in componentWillUnmount?
- What is the purpose of getDerivedStateFromError?
- What is the methods order when component re-rendered?
- What are the methods invoked during error handling?
- What is the purpose of displayName class property?
- What is the browser support for react applications?
- What is the purpose of unmountComponentAtNode method?
- What is code-splitting?
- What is the benefit of strict mode?
- What are Keyed Fragments?
- Does React support all HTML attributes?
- What are the limitations with HOCs?
- How to debug forwardRefs in DevTools?
- When component props defaults to true?
- What is NextJS and major features of it?
- How do you pass an event handler to a component?
- Is it good to use arrow functions in render methods?
- How to prevent a function from being called multiple times?
- How JSX prevents Injection Attacks?
- How do you update rendered elements?
- How do you say that props are read only?
- How do you say that state updates are merged?
- How do you pass arguments to an event handler?
- How to prevent component from rendering?
- What are the conditions to safely use the index as a key?
- Is it keys should be globally unique?
- What is the popular choice for form handling?
- What are the advantages of formik over redux form library?
- Why do you not required to use inheritance?
- Can I use web components in react application?
- What is dynamic import?
- What are loadable components?
- What is suspense component?
- What is route based code splitting?
- Give an example on How to use context?
- What is the purpose of default value in context?
- How do you use contextType?
- What is a consumer?
- How do you solve performance corner cases while using context?
- What is the purpose of forward ref in HOCs?
- Is it ref argument available for all functions or class components?
- Why do you need additional care for component libraries while using forward refs?
- How to create react class components without ES6?
- Is it possible to use react without JSX?
- What is diffing algorithm?
- What are the rules covered by diffing algorithm?
- When do you need to use refs?
- Is it prop must be named as render for render props?
- What are the problems of using render props with pure components?
- How do you create HOC using render props?
- What is windowing technique?
- How do you print falsy values in JSX?
- What is the typical use case of portals?
- How do you set default value for uncontrolled component?
- What is your favorite React stack?
- What is the difference between Real DOM and Virtual DOM?
- How to add Bootstrap to a react application?
- Can you list down top websites or applications using react as front end framework?
- Is it recommended to use CSS In JS technique in React?
- Do I need to rewrite all my class components with hooks?
- How to fetch data with React Hooks?
- Is Hooks cover all use cases for classes?
- What is the stable release for hooks support?
- Why do we use array destructuring (square brackets notation) in useState?
- What are the sources used for introducing hooks?
- How do you access imperative API of web components?
- What is formik?
- What are typical middleware choices for handling asynchronous calls in Redux?
- Do browsers understand JSX code?
- Describe about data flow in react?
- What is react scripts?
- What are the features of create react app?
- What is the purpose of renderToNodeStream method?
- What is MobX?
- What are the differences between Redux and MobX?
- Should I learn ES6 before learning ReactJS?
- What is Concurrent Rendering?
- What is the difference between async mode and concurrent mode?
- Can I use javascript urls in react16.9?
- What is the purpose of eslint plugin for hooks?
- What is the difference between Imperative and Declarative in React?
- What are the benefits of using typescript with reactjs?
- How do you make sure that user remains authenticated on page refresh while using Context API State Management?
- What are the benefits of new JSX transform?
- How does new JSX transform different from old transform?
- How do you get redux scaffolding using create-react-app?
- What are React Server components?
- What is prop drilling?
- What is state mutation and how to prevent it?
- What is the difference between useState and useRef hook?