Questions Code reading Custom Hooks Project patterns
446 items
#1 What is React? Core React #2 What is the history behind React’s evolution? Core React #3 What are the major features of React? Core React #4 What is JSX? Core React #5 What is the difference between an Element and a Component? Core React #6 How do you create components in React? Core React #7 When should you use a Class Component over a Function Component? Core React #8 What are Pure Components? Core React #9 What is state in React? Core React #10 What are props in React? Core React #11 What is the difference between state and props? Core React #12 What is the difference between HTML and React event handling? Core React #13 What are synthetic events in React? Core React #14 What are inline conditional expressions? Core React #15 What is the "key" prop and what is its benefit when used in arrays of elements? Core React #16 What is the Virtual DOM? Core React #17 How does the Virtual DOM work? Core React #18 What is the difference between Shadow DOM and Virtual DOM? Core React #19 What is React Fiber? Core React #20 What is the main goal of React Fiber? Core React #21 What are controlled components? Core React #22 What are uncontrolled components? Core React #23 What is the difference between createElement and cloneElement? Core React #24 What is Lifting State Up in React? Core React #25 What are Higher-Order Components? Core React #26 What is the children prop? Core React #27 How do you write comments in React? Core React #28 What is reconciliation? Core React #29 Does the lazy function support named exports? Core React #30 Why does React use className instead of the class attribute? Core React #31 What are Fragments? Core React #32 Why are Fragments better than container divs? Core React #33 What are portals in React? Core React #34 What are stateless components? Core React #35 What are stateful components? Core React #36 How do you apply validation to props in React? Core React #37 What are the advantages of React? Core React #38 What are the limitations of React? Core React #39 What are the recommended ways for static type checking? Core React #40 What is the use of the react-dom package? Core React #41 What is ReactDOMServer? Core React #42 How do you use innerHTML in React? Core React #43 How do you apply styles in React? Core React #44 How are events different in React? Core React #45 What is the impact of using indexes as keys? Core React #46 How do you conditionally render components? Core React #47 Why do we need to be careful when spreading props on DOM elements? Core React #48 How do you memoize a component? Core React #49 How do you implement Server-Side Rendering (SSR)? Core React #50 How do you enable production mode in React? Core React #51 Do Hooks replace render props and higher-order components? Core React #52 What is a switching component? Core React #54 What are the pointer events supported in React? Core React #55 Why should component names start with a capital letter? Core React #56 Are custom DOM attributes supported in React v16? Core React #57 How do you loop inside JSX? Core React #58 How do you access props within attribute quotes? Core React #59 What is a React PropType array with shape? Core React #60 How do you conditionally apply class attributes? Core React #61 What is the difference between React and ReactDOM? Core React #62 Why is ReactDOM separated from React? Core React #63 How do you use the React label element? Core React #64 How do you combine multiple inline style objects? Core React #65 How do you re-render the view when the browser is resized? Core React #66 How do you pretty-print JSON with React? Core React #67 Why can’t you update props in React? Core React #68 How do you focus an input element on page load? Core React #69 How can you find the version of React at runtime in the browser? Core React #70 How do you add Google Analytics for React Router? Core React #71 How do you apply vendor prefixes to inline styles in React? Core React #72 How do you import and export components using React and ES6? Core React #73 What are the exceptions to React component naming? Core React #74 Is it possible to use async/await in plain React? Core React #75 What are common folder structures for React? Core React #76 What are popular packages for animation? Core React #77 What are the benefits of style modules? Core React #78 What are popular React-specific linters? Core React #79 What is React Router? React Router #80 How is React Router different from the history library? React Router #81 What are the <Router> components of React Router v6? React Router #82 What is the purpose of the push and replace methods of history? React Router #83 How do you programmatically navigate using React Router v4? React Router #84 How do you get query parameters in React Router v4? React Router #85 Why do you get a "Router may have only one child element" warning? React Router #86 How do you pass params to the history.push method in React Router v4? React Router #87 How do you implement a default or NotFound page? React Router #88 How do you get history in React Router v4? React Router #89 How do you perform an automatic redirect after login? React Router #90 What is React Intl? React Internationalization #91 What are the main features of React Intl? React Internationalization #92 What are the two ways of formatting in React Intl? React Internationalization #93 How do you use FormattedMessage as a placeholder with React Intl? React Internationalization #94 How do you access the current locale with React Intl? React Internationalization #95 How do you format a date using React Intl? React Internationalization #96 What is the Shallow Renderer in React testing? React Testing #97 What is the TestRenderer package in React? React Testing #98 What is the purpose of the ReactTestUtils package? React Testing #99 What is Jest? React Testing #100 What are the advantages of Jest over Jasmine? React Testing #101 Can you give a simple example of a Jest test case? React Testing #102 What is Flux? React Redux #103 What is Redux? React Redux #104 What are the core principles of Redux? React Redux #105 What are the downsides of Redux compared to Flux? React Redux #106 What is the difference between mapStateToProps() and mapDispatchToProps()? React Redux #107 Can you dispatch an action in a reducer? React Redux #108 How do you access the Redux store outside a component? React Redux #109 What are the drawbacks of the MVW pattern? React Redux #110 Are there any similarities between Redux and RxJS? React Redux #111 How do you reset state in Redux? React Redux #112 What is the difference between React Context and React Redux? React Redux #113 Why are Redux state functions called reducers? React Redux #114 How do you make an AJAX request in Redux? React Redux #115 Should you keep all component states in the Redux store? React Redux #116 What is the proper way to access the Redux store? React Redux #117 What is the difference between a component and a container in React Redux? React Redux #118 What is the purpose of constants in Redux? React Redux #119 What are the different ways to write mapDispatchToProps()? React Redux #120 What is the use of the ownProps parameter in mapStateToProps() and mapDispatchToProps()? React Redux #121 How do you structure Redux top-level directories? React Redux #122 What is Redux Saga? React Redux #123 What is the mental model of Redux Saga? React Redux #124 What are the differences between call and put in Redux Saga? React Redux #125 What is Redux Thunk? React Redux #126 What are the differences between Redux Saga and Redux Thunk? React Redux #127 What is Redux DevTools? React Redux #128 What are the features of Redux DevTools? React Redux #129 What are Redux selectors and why should you use them? React Redux #130 What is Redux Form? React Redux #131 What are the main features of Redux Form? React Redux #132 How do you add multiple middlewares to Redux? React Redux #133 How do you set the initial state in Redux? React Redux #134 How is Relay different from Redux? React Redux #135 What is an action in Redux? React Redux #136 What is the difference between React Native and React? React Native #137 How do you test React Native apps? React Native #138 How do you log in React Native? React Native #139 How do you debug React Native apps? React Native #140 What is Reselect and how does it work? React Supported Libraries and Integration #141 What is Flow? React Supported Libraries and Integration #142 What is the difference between Flow and PropTypes? React Supported Libraries and Integration #143 How do you use Font Awesome icons in React? React Supported Libraries and Integration #144 What is React DevTools? React Supported Libraries and Integration #145 Why does DevTools not load in Chrome for local files? React Supported Libraries and Integration #146 How do you use Polymer in React? React Supported Libraries and Integration #147 What are the advantages of React over Vue.js? React Supported Libraries and Integration #148 What is the difference between React and Angular? React Supported Libraries and Integration #149 Why is the React tab not showing up in DevTools? React Supported Libraries and Integration #150 What are styled-components? React Supported Libraries and Integration #151 Can you give an example of styled-components? React Supported Libraries and Integration #152 What is Relay? React Supported Libraries and Integration #153 What are the main features of the Reselect library? Miscellaneous #154 Can you give an example of Reselect usage? Miscellaneous #155 Can Redux only be used with React? Miscellaneous #156 Do you need a specific build tool to use Redux? Miscellaneous #157 How do Redux Form initial values get updated from state? Miscellaneous #158 How do React PropTypes allow different types for one prop? Miscellaneous #159 Can you import an SVG file as a React component? Miscellaneous #160 What is render hijacking in React? Miscellaneous #161 How do you pass numbers to a React component? Miscellaneous #162 Do you need to keep all state in Redux? Should you ever use React’s internal state? Miscellaneous #163 What is the purpose of registerServiceWorker in React? Miscellaneous #164 What is the React.memo function? Miscellaneous #165 What is the React.lazy function? Miscellaneous #166 How do you prevent unnecessary updates using setState? Miscellaneous #167 How do you render arrays, strings, and numbers in React v16? Miscellaneous #168 What are Hooks? Miscellaneous #169 What rules must be followed for Hooks? Miscellaneous #170 How do you ensure Hooks follow the rules in your project? Miscellaneous #171 What are the differences between Flux and Redux? Miscellaneous #172 What are the benefits of React Router v4? Miscellaneous #173 Can you describe the componentDidCatch lifecycle method signature? Miscellaneous #174 In which scenarios do error boundaries not catch errors? Miscellaneous #175 What is the behavior of uncaught errors in React v16? Miscellaneous #176 What is the proper placement for error boundaries? Miscellaneous #177 What is the benefit of a component stack trace from an error boundary? Miscellaneous #178 What are default props? Miscellaneous #179 What is the purpose of the displayName class property? Miscellaneous #180 What is the browser support for React applications? Miscellaneous #181 What is code-splitting? Miscellaneous #182 What are keyed Fragments? Miscellaneous #183 Does React support all HTML attributes? Miscellaneous #184 When do component props default to true? Miscellaneous #185 What is Next.js and what are its major features? Miscellaneous #186 How do you pass an event handler to a component? Miscellaneous #187 How do you prevent a function from being called multiple times? Miscellaneous #188 How does JSX prevent injection attacks? Miscellaneous #189 How do you update rendered elements? Miscellaneous #190 How do you indicate that props are read-only? Miscellaneous #191 What are the conditions for safely using an index as a key? Miscellaneous #192 Do keys need to be globally unique? Miscellaneous #193 What is the popular choice for form handling? Miscellaneous #194 What are the advantages of Formik over the Redux Form library? Miscellaneous #195 Why are you not required to use inheritance? Miscellaneous #196 Can you use web components in a React application? Miscellaneous #197 What is a dynamic import? Miscellaneous #198 What are loadable components? Miscellaneous #199 What is a Suspense component? Miscellaneous #200 What is route-based code splitting? Miscellaneous #201 What is the purpose of the default value in Context? Miscellaneous #202 What is the diffing algorithm? Miscellaneous #203 What rules are covered by the diffing algorithm? Miscellaneous #204 When do you need to use refs? Miscellaneous #205 Must a prop be named "render" for render props? Miscellaneous #206 What are the problems with using render props with Pure Components? Miscellaneous #207 What is the windowing technique? Miscellaneous #208 How do you print falsy values in JSX? Miscellaneous #209 What is the typical use case for portals? Miscellaneous #210 How do you set a default value for an uncontrolled component? Miscellaneous #211 What is your favorite React stack? Miscellaneous #212 What is the difference between the real DOM and the Virtual DOM? Miscellaneous #213 How do you add Bootstrap to a React application? Miscellaneous #214 Can you list the top websites or applications using React as a front-end framework? Miscellaneous #215 Is it recommended to use the CSS-in-JS technique in React? Miscellaneous #216 Do you need to rewrite all class components with Hooks? Miscellaneous #217 How do you fetch data with React Hooks? Miscellaneous #218 Do Hooks cover all use cases for classes? Miscellaneous #219 What is the stable release for Hooks support? Miscellaneous #220 Why do we use array destructuring (square bracket notation) in useState? Miscellaneous #221 What sources were used for introducing Hooks? Miscellaneous #222 How do you access the imperative API of web components? Miscellaneous #223 What is Formik? Miscellaneous #224 What are typical middleware choices for handling asynchronous calls in Redux? Miscellaneous #225 Do browsers understand JSX code? Miscellaneous #226 Can you describe data flow in React? Miscellaneous #227 What is MobX? Miscellaneous #228 What are the differences between Redux and MobX? Miscellaneous #229 Should you learn ES6 before learning ReactJS? Miscellaneous #230 Explain concurrent rendering with an example Miscellaneous #231 What is the difference between async mode and concurrent mode? Miscellaneous #233 What is the purpose of the ESLint plugin for Hooks? Miscellaneous #234 What is the difference between imperative and declarative programming in React? Miscellaneous #235 What are the benefits of using TypeScript with ReactJS? Miscellaneous #236 How do you ensure a user remains authenticated on page refresh while using Context API state management? Miscellaneous #237 What are the benefits of the new JSX transform? Miscellaneous #238 How is the new JSX transform different from the old transform? Miscellaneous #239 What are React Server Components? Miscellaneous #240 What is prop drilling? Miscellaneous #241 What is the difference between the useState and useRef Hooks? Miscellaneous #242 What is a wrapper component? Miscellaneous #243 What are the differences between the useEffect and useLayoutEffect Hooks? Miscellaneous #244 What are the differences between functional and class components? Miscellaneous #245 What is Strict Mode in React? Miscellaneous #246 What is the benefit of Strict Mode? Miscellaneous #247 Why does Strict Mode render twice in React? Miscellaneous #248 What are the rules of JSX? Miscellaneous #249 What is the reason multiple JSX tags must be wrapped? Miscellaneous #250 How do you prevent mutating array variables? Miscellaneous #251 What are capture phase events? Miscellaneous #252 How does React update the screen in an application? Miscellaneous #253 How does React batch multiple state updates? Miscellaneous #254 Is it possible to prevent automatic batching? Miscellaneous #255 What is React hydration? Miscellaneous #256 How do you update objects inside state? Miscellaneous #257 How do you update nested objects inside state? Miscellaneous #258 How do you update arrays inside state? Miscellaneous #259 How do you use the Immer library for state updates? Miscellaneous #260 What are the benefits of preventing direct state mutations? Miscellaneous #261 What are the preferred and non-preferred array operations for updating state? Miscellaneous #262 What will happen when defining nested function components? Miscellaneous #263 Can I use keys for non-list items? Miscellaneous #264 What are the guidelines to follow for writing reducers? Miscellaneous #265 What is useReducer hook? Can you describe its usage? Hooks #266 How do you compare useState and useReducer? Hooks #267 How does Context work with the useContext hook? Hooks #268 What are the use cases of the useContext hook? Hooks #269 When should you use client and server components? Hooks #270 What are the differences between the Page Router and App Router in Next.js? Hooks #271 Can you describe the useMemo() Hook? Hooks #272 Can Hooks be used in class components? Hooks #273 What is an updater function? Should an updater function be used in all cases? Hooks #274 Can useState take a function as an initial value? Hooks #275 What types of values can useState hold? Hooks #276 What happens if you call useState conditionally? Hooks #277 Is useState Synchronous or Asynchronous? Hooks #278 Can you explain how useState works internally? Hooks #279 What is useReducer? Why do you use useReducer? Hooks #280 How does useReducer work? Explain with an example Hooks #281 Can you combine useReducer with useContext? Hooks #282 Can you dispatch multiple actions in a row with useReducer? Hooks #283 Is dispatch from useReducer asynchronous and does it update state immediately? Hooks #284 How does useContext work? Explain with an example Hooks #285 Can you use multiple Contexts in one component? Hooks #286 What's a common pitfall when using useContext with objects? Hooks #287 What would the context value be for no matching provider? Hooks #288 How do reactive dependencies in the useEffect dependency array affect its execution behavior? Hooks #289 When and how often does React invoke the setup and cleanup functions inside a useEffect hook? Hooks #290 What happens if you return a Promise from useEffect? Hooks #291 Can you have multiple useEffect hooks in a single component? Hooks #292 How to prevent infinite loops with useEffect? Hooks #293 What are the use cases of useLayoutEffect? Hooks #294 How does useLayoutEffect work during server-side rendering (SSR)? Hooks #295 What happens if you use useLayoutEffect for non-layout logic? Hooks #296 How does useLayoutEffect cause layout thrashing? Hooks #297 How do you use useRef to access a DOM element in React? Give an example Hooks #298 Can you use useRef to persist values across renders? Hooks #299 Can useRef be used to store previous values? Hooks #300 Is it possible to access a ref in the render method? Hooks #301 What are the common use cases of useRef hook? Hooks #302 What is useImperativeHandle Hook? Give an example Hooks #303 When should you use useImperativeHandle? Hooks #304 Is it possible to use useImperativeHandle without forwardRef? Hooks #305 How is useMemo different from useCallback? Hooks #306 Does useMemo prevent re-rendering of child components? Hooks #307 What is useCallback and why is it used? Hooks #308 What are Custom React Hooks, and how can you develop one? Hooks #309 How does React Fiber work? Explain in detail Hooks #310 What is the useId hook and when should you use it? Hooks #311 What is the useDeferredValue hook? Hooks #312 What is the useTransition hook and how does it differ from useDeferredValue? Hooks #313 What is the useSyncExternalStore hook? Hooks #314 What is the useInsertionEffect hook? Hooks #315 How do you share state logic between components using custom hooks? Hooks #316 What is the useDebugValue hook? Hooks #317 How do you handle cleanup in useEffect? Hooks #318 What are the differences between useEffect and useEvent (experimental)? Hooks #319 What are the best practices for using React Hooks? Hooks #320 What are the key features introduced in React 18? Modern React Features (React 18/19) #321 What are the key features introduced in React 19? Modern React Features (React 18/19) #322 What is the use() hook in React 19? Modern React Features (React 18/19) #323 What are Server Actions in React 19? Modern React Features (React 18/19) #324 What are useFormState and useFormStatus hooks? Modern React Features (React 18/19) #325 What is the useOptimistic hook? Modern React Features (React 18/19) #326 What is the React Compiler (React Forget)? Modern React Features (React 18/19) #327 What is Streaming SSR and how does React 18+ improve it? Modern React Features (React 18/19) #328 What is renderToPipeableStream and how is it different from renderToString? Modern React Features (React 18/19) #329 What is the difference between HOCs and Hooks? Modern React Features (React 18/19) #330 Does React.memo prevent Context consumers from re-rendering? Modern React Features (React 18/19) #331 How would you create a reusable Context? Modern React Features (React 18/19) #332 Why is Redux Toolkit recommended over Redux? Modern React Features (React 18/19) #333 What is the difference between client state and server state? Modern React Features (React 18/19) #334 How do you prevent unnecessary Redux re-renders? Modern React Features (React 18/19) #335 What is createSelector? Modern React Features (React 18/19) #336 What is normalized Redux state? Modern React Features (React 18/19) #337 Why is normalized state important for performance? Modern React Features (React 18/19) #338 What is Redux middleware? Modern React Features (React 18/19) #339 What is the Redux middleware signature? Modern React Features (React 18/19) #340 What happens when you dispatch an action? Modern React Features (React 18/19) #341 How would you structure Redux in a large application? Modern React Features (React 18/19) #342 How do you handle cross-slice communication? Modern React Features (React 18/19) #343 What are Redux serializable values? Modern React Features (React 18/19) #344 How do you handle race conditions in Redux? Modern React Features (React 18/19) #345 How do you persist Redux state? Modern React Features (React 18/19) #346 How do you debug a Redux performance problem? Modern React Features (React 18/19) #347 What should be stored in Redux vs derived with selectors? Modern React Features (React 18/19) #348 Would you put all API data into Redux? Modern React Features (React 18/19) #349 What is the difference between BrowserRouter, HashRouter, and MemoryRouter? Modern React Features (React 18/19) #350 What are dynamic routes and what are route parameters? Modern React Features (React 18/19) #351 How do you navigate programmatically in React Router? Modern React Features (React 18/19) #352 What is the difference between Link, NavLink, and <a>? Modern React Features (React 18/19) #353 How do you implement protected/private routes? Modern React Features (React 18/19) #354 How do you handle 404 / Not Found routes? Modern React Features (React 18/19) #355 What are loaders, actions, and data APIs in modern React Router? Modern React Features (React 18/19) #356 How do query parameters work? Modern React Features (React 18/19) What is Concurrent Rendering? (Legacy) Old Q&A #1 Why should we not update the state directly? Old Q&A #2 What is the purpose of callback function as an argument of setState()? Old Q&A #3 How to bind methods or event handlers in JSX callbacks? Old Q&A #4 How to pass a parameter to an event handler or callback? Old Q&A #5 What is the use of refs? Old Q&A #6 How to create refs? Old Q&A #7 What are forward refs? Old Q&A #8 Which is preferred option with in callback refs and findDOMNode()? Old Q&A #9 Why are String Refs legacy? Old Q&A #10 What are the different phases of component lifecycle? Old Q&A #11 What are the lifecycle methods of React? Old Q&A #12 How to create props proxy for HOC component? Old Q&A #13 What is context? Old Q&A #14 What is the purpose of using super constructor with props argument? Old Q&A #15 How to set state with a dynamic key name? Old Q&A #16 What would be the common mistake of function being called every time the component renders? Old Q&A #17 What are error boundaries in React v16 Old Q&A #18 How are error boundaries handled in React v15? Old Q&A #19 What is the purpose of render method of react-dom? Old Q&A #20 What will happen if you use setState in constructor? Old Q&A #21 Is it good to use setState() in componentWillMount() method? Old Q&A #22 What will happen if you use props in initial state? Old Q&A #23 How you use decorators in React? Old Q&A #24 What is CRA and its benefits? Old Q&A #25 What is the lifecycle methods order in mounting? Old Q&A #26 What are the lifecycle methods going to be deprecated in React v16? Old Q&A #27 What is the purpose of getDerivedStateFromProps() lifecycle method? Old Q&A #28 What is the purpose of getSnapshotBeforeUpdate() lifecycle method? Old Q&A #29 What is the recommended way for naming components? Old Q&A #30 What is the recommended ordering of methods in component class? Old Q&A #31 Why we need to pass a function to setState()? Old Q&A #32 Why is isMounted() an anti-pattern and what is the proper solution? Old Q&A #33 What is the difference between constructor and getInitialState? Old Q&A #34 Can you force a component to re-render without calling setState? Old Q&A #35 What is the difference between super() and super(props) in React using ES6 classes? Old Q&A #36 What is the difference between setState and replaceState methods? Old Q&A #37 How to listen to state changes? Old Q&A #38 What is the recommended approach of removing an array element in react state? Old Q&A #39 Is it possible to use React without rendering HTML? Old Q&A #40 What are the possible ways of updating objects in state? Old Q&A #41 What are the approaches to include polyfills in your create-react-app? Old Q&A #42 How to use https instead of http in create-react-app? Old Q&A #43 How to avoid using relative path imports in create-react-app? Old Q&A #44 How to update a component every second? Old Q&A #45 Why is a component constructor called only once? Old Q&A #46 How to define constants in React? Old Q&A #47 How to programmatically trigger click event in React? Old Q&A #48 How to make AJAX call and In which component lifecycle methods should I make an AJAX call? Old Q&A #49 What are render props? Old Q&A #50 How to dispatch an action on load? Old Q&A #51 How to use connect from React Redux? Old Q&A #52 Whats the purpose of at symbol in the redux connect decorator? Old Q&A #53 How to use TypeScript in create-react-app application? Old Q&A #54 Does the statics object work with ES6 classes in React? Old Q&A #55 Why are inline ref callbacks or functions not recommended? Old Q&A #56 What are HOC factory implementations? Old Q&A #57 How to use class field declarations syntax in React classes? Old Q&A #58 Why do you not need error boundaries for event handlers? Old Q&A #59 What is the difference between try catch block and error boundaries? Old Q&A #60 What is the required method to be defined for a class component? Old Q&A #61 What are the possible return types of render method? Old Q&A #62 What is the main purpose of constructor? Old Q&A #63 Is it mandatory to define constructor for React component? Old Q&A #64 Why should not call setState in componentWillUnmount? Old Q&A #65 What is the purpose of getDerivedStateFromError? Old Q&A #66 What is the methods order when component re-rendered? Old Q&A #67 What are the methods invoked during error handling? Old Q&A #68 What is the purpose of unmountComponentAtNode method? Old Q&A #69 What are the limitations with HOCs? Old Q&A #70 How to debug forwardRefs in DevTools? Old Q&A #71 Is it good to use arrow functions in render methods? Old Q&A #72 How do you say that state updates are merged? Old Q&A #73 How do you pass arguments to an event handler? Old Q&A #74 How to prevent component from rendering? Old Q&A #75 Give an example on How to use context? Old Q&A #76 How do you use contextType? Old Q&A #77 What is a consumer? Old Q&A #78 How do you solve performance corner cases while using context? Old Q&A #79 What is the purpose of forward ref in HOCs? Old Q&A #80 Is it ref argument available for all functions or class components? Old Q&A #81 Why do you need additional care for component libraries while using forward refs? Old Q&A #82 How to create react class components without ES6? Old Q&A #83 Is it possible to use react without JSX? Old Q&A #84 How do you create HOC using render props? Old Q&A #85 What is react scripts? Old Q&A #86 What are the features of create react app? Old Q&A #87 What is the purpose of renderToNodeStream method? Old Q&A #88 How do you get redux scaffolding using create-react-app? Old Q&A #89 What is state mutation and how to prevent it? Old Q&A #90 What are React Mixins? Old Q&A #91 Can I use javascript urls in react16.9? Old Q&A
REACT Core React junior
Source question #1 What is React? React (aka React.js or ReactJS) is an open-source front-end JavaScript library for building user interfaces based on components. It's used for handling the view layer in web and mobile applications, and allows developers to create reusable UI components and manage the state of those components efficiently.
React was created by Jordan Walke, a software engineer at Facebook (now Meta). It was first deployed on Facebook's News Feed in 2011 and on Instagram in 2012. The library was open-sourced in May 2013 and has since become one of the most popular JavaScript libraries for building modern user interfaces.
