React JS FAQs Final Set 1

 

React JS FAQS Final Set 1

 

1.       What is React?

2.       What are the key features of React?

3.       How does React differ from other JavaScript frameworks?

4.       Explain the Virtual DOM in React.

5.       What is JSX?

6.       What are the advantages of using JSX?

7.       How do you define a React component?

8.       What is the difference between functional and class components?

9.       How do you create a stateful component in React?

10.   What is the significance of setState() in React?

11.   Explain the lifecycle methods of a class component.

12.   What is the componentDidMount() method used for?

13.   How can you prevent unnecessary re-renders in React?

14.   What are the controlled and uncontrolled components in React?

15.   How do you handle events in React?

16.   What is the use of ref in React?

17.   What are React Hooks? How do they work?

18.   Explain useState() and useEffect() hooks.

19.   What is the useContext() hook used for?

20.   How do you handle forms in React?

21.   What is React Router, and how do you use it?

22.   Explain the concept of higher-order components (HOCs) in React.

23.   What is the purpose of keys in React lists?

24.   How can you optimize performance in React applications?

25.   What are React fragments?

26.   How can you handle errors in React?

27.   What is Redux, and why is it used in React applications?

28.   What are the key principles of Redux?

29.   Explain the Flux architecture pattern.

30.   How do you connect a Redux store to a React component?

31.   What is a reducer in Redux?

32.   How do you handle asynchronous actions in Redux?

33.   What is Redux Thunk?

34.   How can you implement server-side rendering (SSR) in React?

35.   What are the different lifecycle methods in React Hooks?

36.   How do you perform unit testing in React applications?

37.   Explain React PropTypes.

38.   What are React portals, and how do you use them?

39.   How do you handle forms with validation in React?

40.   What are React DevTools, and how can you use them?

41.   Explain React lazy and Suspense.

42.   How do you implement code splitting in React?

43.   What are the differences between React and Angular?

44.   How can you share state between components using React context?

45.   What is React.memo() used for?

46.   How can you handle routing in a single-page application (SPA) using React?

47.   Explain React.forwardRef() and its use case.

48.   What is the significance of shouldComponentUpdate() method in React?

49.   How do you create a reusable component in React?

50.   Explain the concept of controlled vs. uncontrolled inputs in React.

51.   How do you use the create-react-app tool?

52.   What is React Fiber, and how does it improve performance?

53.   How can you handle authentication and authorization in React applications?

54.   Explain the concept of code-splitting in React Router.

55.   What is React.memo() used for?

56.   How can you handle routing in a single-page application (SPA) using React?

57.   Explain React.forwardRef() and its use case.

58.   What is the significance of shouldComponentUpdate() method in React?

59.   How do you create a reusable component in React?

60.   Explain the concept of controlled vs. uncontrolled inputs in React.

61.   How do you use the create-react-app tool?

62.   What is React Fiber, and how does it improve performance?

63.   How can you handle authentication and authorization in React applications?

64.   Explain the concept of code-splitting in React Router.

65.   What is React.memo() used for?

66.   How can you handle routing in a single-page application (SPA) using React?

67.   Explain React.forwardRef() and its use case.

68.   What is the significance of shouldComponentUpdate() method in React?

69.   How do you create a reusable component in React?

70.   Explain the concept of controlled vs. uncontrolled inputs in React.

71.   How do you use the create-react-app tool?

72.   What is React Fiber, and how does it improve performance?

73.   How can you handle authentication and authorization in React applications?

74.   Explain the concept of code-splitting in React Router.

75.   What are React fragments?

76.   How do you handle errors in React?

77.   What is Redux, and why is it used in React applications?

78.   What are the key principles of Redux?

79.   Explain the Flux architecture pattern.

80.   How do you connect a Redux store to a React component?

81.   What is a reducer in Redux?

82.   How do you handle asynchronous actions in Redux?

83.   What is Redux Thunk?

84.   How can you implement server-side rendering (SSR) in React?

85.   What are the different lifecycle methods in React Hooks?

86.   How do you perform unit testing in React applications?

87.   Explain React PropTypes.

88.   What are React portals, and how do you use them?

89.   How do you handle forms with validation in React?

90.   What are React DevTools, and how can you use them?

91.   Explain React lazy and Suspense.

92.   How do you implement code splitting in React?

93.   What are the differences between React and Angular?

94.   How can you share state between components using React context?

95.   What is React.memo() used for?

96.   How can you handle routing in a single-page application (SPA) using React?

97.   Explain React.forwardRef() and its use case.

98.   What is the significance of shouldComponentUpdate() method in React?

99.   How do you create a reusable component in React?

100.                        Explain the concept of controlled vs. uncontrolled inputs in React.

101.                        How do you use the create-react-app tool?

102.                        What is React Fiber, and how does it improve performance?

103.                        How can you handle authentication and authorization in React applications?

104.                        Explain the concept of code-splitting in React Router.

105.                        What is React.memo() used for?

106.                        How can you handle routing in a single-page application (SPA) using React?

107.                        Explain React.forwardRef() and its use case.

108.                        What is the significance of shouldComponentUpdate() method in React?

109.                        How do you create a reusable component in React?

110.                        Explain the concept of controlled vs. uncontrolled inputs in React.

111.                        How do you use the create-react-app tool?

112.                        What is React Fiber, and how does it improve performance?

113.                        How can you handle authentication and authorization in React applications?

114.                        Explain the concept of code-splitting in React Router.

115.                        What are React fragments?

116.                        How do you handle errors in React?

117.                        What is Redux, and why is it used in React applications?

118.                        What are the key principles of Redux?

119.                        Explain the Flux architecture pattern.

120.                        How do you connect a Redux store to a React component?

121.                        What is a reducer in Redux?

122.                        How do you handle asynchronous actions in Redux?

123.                        What is Redux Thunk?

124.                        How can you implement server-side rendering (SSR) in React?

125.                        What are the different lifecycle methods in React Hooks?

126.                        How do you perform unit testing in React applications?

127.                        Explain React PropTypes.

128.                        What are React portals, and how do you use them?

129.                        How do you handle forms with validation in React?

130.                        What are React DevTools, and how can you use them?

131.                        Explain React lazy and Suspense.

132.                        How do you implement code splitting in React?

133.                        What are the differences between React and Angular?

134.                        How can you share state between components using React context?

135.                        What is React.memo() used for?

136.                        How can you handle routing in a single-page application (SPA) using React?

137.                        Explain React.forwardRef() and its use case.

138.                        What is the significance of shouldComponentUpdate() method in React?

139.                        How do you create a reusable component in React?

140.                        Explain the concept of controlled vs. uncontrolled inputs in React.

141.                        How do you use the create-react-app tool?

142.                        What is React Fiber, and how does it improve performance?

143.                        How can you handle authentication and authorization in React applications?

144.                        Explain the concept of code-splitting in React Router.

145.                        What is React.memo() used for?

146.                        How can you handle routing in a single-page application (SPA) using React?

147.                        Explain React.forwardRef() and its use case.

148.                        What is the significance of shouldComponentUpdate() method in React?

149.                        How do you create a reusable component in React?

150.                        Explain the concept of controlled vs. uncontrolled inputs in React.

151.                        How do you use the create-react-app tool?

152.                        What is React Fiber, and how does it improve performance?

153.                        How can you handle authentication and authorization in React applications?

154.                        Explain the concept of code-splitting in React Router.

155.                        What are React fragments?

156.                        How do you handle errors in React?

157.                        What is Redux, and why is it used in React applications?

158.                        What are the key principles of Redux?

159.                        Explain the Flux architecture pattern.

160.                        How do you connect a Redux store to a React component?

161.                        What is a reducer in Redux?

162.                        How do you handle asynchronous actions in Redux?

163.                        What is Redux Thunk?

164.                        How can you implement server-side rendering (SSR) in React?

165.                        What are the different lifecycle methods in React Hooks?

166.                        How do you perform unit testing in React applications?

167.                        Explain React PropTypes.

168.                        What are React portals, and how do you use them?

169.                        How do you handle forms with validation in React?

170.                        What are React DevTools, and how can you use them?

171.                        Explain React lazy and Suspense.

172.                        How do you implement code splitting in React?

173.                        What are the differences between React and Angular?

174.                        How can you share state between components using React context?

175.                        What is React.memo() used for?

176.                        How can you handle routing in a single-page application (SPA) using React?

177.                        Explain React.forwardRef() and its use case.

178.                        What is the significance of shouldComponentUpdate() method in React?

179.                        How do you create a reusable component in React?

180.                        Explain the concept of controlled vs. uncontrolled inputs in React.

181.                        How do you use the create-react-app tool?

182.                        What is React Fiber, and how does it improve performance?

183.                        How can you handle authentication and authorization in React applications?

184.                        Explain the concept of code-splitting in React Router.

185.                        What is React.memo() used for?

186.                        How can you handle routing in a single-page application (SPA) using React?

187.                        Explain React.forwardRef() and its use case.

188.                        What is the significance of shouldComponentUpdate() method in React?

189.                        How do you create a reusable component in React?

190.                        Explain the concept of controlled vs. uncontrolled inputs in React.

191.                        How do you use the create-react-app tool?

192.                        What is React Fiber, and how does it improve performance?

193.                        How can you handle authentication and authorization in React applications?

194.                        Explain the concept of code-splitting in React Router.

195.                        What are React fragments?

196.                        How do you handle errors in React?

197.                        What is Redux, and why is it used in React applications?

198.                        What are the key principles of Redux?

199.                        Explain the Flux architecture pattern.

200.                        How do you connect a Redux store to a React component?

201.                        What is a reducer in Redux?

202.                        How do you handle asynchronous actions in Redux?

203.                        What is Redux Thunk?

204.                        How can you implement server-side rendering (SSR) in React?

205.                        What are the different lifecycle methods in React Hooks?

206.                        How do you perform unit testing in React applications?

207.                        Explain React PropTypes.

208.                        What are React portals, and how do you use them?

209.                        How do you handle forms with validation in React?

210.                        What are React DevTools, and how can you use them?

211.                        Explain React lazy and Suspense.

212.                        How do you implement code splitting in React?

213.                        What are the differences between React and Angular?

214.                        How can you share state between components using React context?

215.                        What is React.memo() used for?

216.                        How can you handle routing in a single-page application (SPA) using React?

217.                        Explain React.forwardRef() and its use case.

218.                        What is the significance of shouldComponentUpdate() method in React?

219.                        How do you create a reusable component in React?

220.                        Explain the concept of controlled vs. uncontrolled inputs in React.

221.                        How do you use the create-react-app tool?

222.                        What is React Fiber, and how does it improve performance?

223.                        How can you handle authentication and authorization in React applications?

224.                        Explain the concept of code-splitting in React Router.

225.                        What is React.memo() used for?

226.                        How can you handle routing in a single-page application (SPA) using React?

227.                        Explain React.forwardRef() and its use case.

228.                        What is the significance of shouldComponentUpdate() method in React?

229.                        How do you create a reusable component in React?

230.                        Explain the concept of controlled vs. uncontrolled inputs in React.

231.                        How do you use the create-react-app tool?

232.                        What is React Fiber, and how does it improve performance?

233.                        How can you handle authentication and authorization in React applications?

234.                        Explain the concept of code-splitting in React Router.

235.                        What are React fragments?

236.                        How do you handle errors in React?

237.                        What is Redux, and why is it used in React applications?

238.                        What are the key principles of Redux?

239.                        Explain the Flux architecture pattern.

240.                        How do you connect a Redux store to a React component?

241.                        What is a reducer in Redux?

242.                        How do you handle asynchronous actions in Redux?

243.                        What is Redux Thunk?

244.                        How can you implement server-side rendering (SSR) in React?

245.                        What are the different lifecycle methods in React Hooks?

246.                        How do you perform unit testing in React applications?

247.                        Explain React PropTypes.

248.                        What are React portals, and how do you use them?

249.                        How do you handle forms with validation in React?

250.                        What are React DevTools, and how can you use them?

 

 

 

 

 

 

 

 

React JS FAQS Final Set 2

 

1.       Describe a complex React project you have worked on and explain your role in it.

2.       How do you handle performance optimization in React applications?

3.       Explain how you handle state management in large-scale React applications.

4.       Have you worked with Redux? If so, describe a situation where you used it and why.

5.       How do you handle asynchronous actions in React applications?

6.       Describe a situation where you had to integrate a third-party library with React and explain the challenges you faced.

7.       How do you handle form validation in React?

8.       Have you used React Router? Describe a scenario where you implemented routing in a React application.

9.       Explain how you handle authentication and authorization in React applications.

10.   Describe your experience with server-side rendering (SSR) in React and the benefits it provides.

11.   How do you handle internationalization (i18n) in React applications?

12.   Describe a scenario where you had to handle complex state synchronization between multiple components in React.

13.   Explain how you ensure code reusability and maintainability in your React projects.

14.   Describe a situation where you encountered a performance bottleneck in a React application and how you resolved it.

15.   How do you handle error handling and logging in React applications?

16.   Describe your experience with integrating APIs with React applications and any challenges you faced.

17.   Explain how you ensure cross-browser compatibility in React projects.

18.   Describe a scenario where you had to implement real-time updates or notifications in a React application.

19.   How do you handle unit testing in React applications? Which testing frameworks and libraries do you prefer?

20.   Explain your approach to code review and how you ensure code quality in React projects.

21.   Describe a scenario where you had to refactor a React component for improved performance or maintainability.

22.   How do you handle version control and collaboration in React projects? Which tools do you use?

23.   Explain your experience with continuous integration and deployment (CI/CD) in React applications.

24.   Describe a scenario where you had to handle data caching and synchronization in a React application.

25.   How do you ensure accessibility (a11y) in your React projects?

26.   Explain your approach to handling responsive design and mobile optimization in React applications.

27.   Describe a scenario where you had to implement complex animations or transitions in a React application.

28.   How do you handle state persistence (e.g., local storage, session storage) in React applications?

29.   Explain your approach to code splitting and lazy loading in React projects.

30.   Describe a scenario where you had to integrate a third-party UI library or component in a React application.

31.   How do you handle localization (l10n) in React applications?

32.   Explain your approach to handling SEO optimization in React projects.

33.   Describe a situation where you had to handle data fetching and management with GraphQL in a React application.

34.   How do you handle data flow and communication between components in React?

35.   Explain your experience with handling complex forms with dynamic fields in React applications.

36.   Describe a scenario where you had to implement user authentication and role-based permissions in a React application.

37.   How do you handle caching and memoization of computed values in React?

38.   Explain your approach to handling client-side routing and navigation in React projects.

39.   Describe a scenario where you had to implement a custom data visualization or charting component in a React application.

40.   How do you handle data normalization and denormalization in React applications?

41.   Explain your experience with integrating WebSocket or real-time communication in a React application.

42.   Describe a situation where you had to implement drag-and-drop functionality in a React application.

43.   How do you handle performance monitoring and error tracking in React projects?

44.   Explain your approach to handling server-side validation and error messages in React forms.

45.   Describe a scenario where you had to implement a complex UI interaction or state machine in a React application.

46.   How do you handle image optimization and lazy loading of images in React projects?

47.   Explain your experience with implementing client-side caching and offline support in a React application.

48.   Describe a situation where you had to optimize the rendering performance of a large React component tree.

49.   How do you handle API pagination and infinite scrolling in React applications?

50.   Explain your approach to handling complex data transformations and computations in React projects.

51.   Describe a scenario where you had to implement a complex search or filtering functionality in a React application.

52.   How do you handle code modularity and organization in large-scale React projects?

53.   Explain your experience with integrating payment gateways or e-commerce functionality in a React application.

54.   Describe a situation where you had to handle user-generated content and input sanitization in a React application.

55.   How do you handle graceful degradation and progressive enhancement in React projects?

56.   Explain your approach to handling concurrent requests and request throttling in React applications.

57.   Describe a scenario where you had to implement offline support and data synchronization in a React application.

58.   How do you handle user experience (UX) optimization and performance in React projects?

59.   Explain your experience with implementing real-time collaboration or multiplayer functionality in a React application.

60.   Describe a situation where you had to optimize the bundle size and reduce the initial load time of a React application.

61.   How do you handle data encryption and secure communication in React projects?

62.   Explain your approach to handling user preferences and settings in a React application.

63.   Describe a scenario where you had to implement social media integration or sharing in a React application.

64.   How do you handle data validation and sanitization in React applications?

65.   Explain your experience with implementing user analytics and tracking in a React application.

66.   Describe a situation where you had to handle complex data synchronization and conflict resolution in a React application.

67.   How do you handle component styling and CSS management in React projects?

68.   Explain your approach to handling SEO-friendly URLs and routing in React applications.

69.   Describe a scenario where you had to implement complex data visualization or charting using D3.js with React.

70.   How do you handle data migration and versioning in React projects?

71.   Explain your experience with integrating chat or messaging functionality in a React application.

72.   Describe a situation where you had to optimize network requests and reduce the number of API calls in a React application.

73.   How do you handle permission-based data access and data security in React projects?

74.   Explain your approach to handling concurrency and data consistency in React applications.

75.   Describe a scenario where you had to implement offline forms with data synchronization in a React application.

76.   How do you handle A/B testing and feature flagging in React projects?

77.   Explain your experience with implementing virtualization and lazy loading of large lists in React applications.

78.   Describe a situation where you had to integrate a React application with a legacy system or external service.

79.   How do you handle error recovery and fallback mechanisms in React projects?

80.   Explain your approach to handling responsive images and optimizing image assets in React applications.

81.   Describe a scenario where you had to implement user-generated content moderation and filtering in a React application.

82.   How do you handle data consistency and synchronization between client and server in React projects?

83.   Explain your experience with implementing user notifications and alerts in a React application.

84.   Describe a situation where you had to optimize the rendering performance of a React Native mobile application.

85.   How do you handle accessibility considerations for users with disabilities in React projects?

86.   Explain your approach to handling multi-language support and localization in React applications.

87.   Describe a scenario where you had to implement user onboarding and walkthroughs in a React application.

88.   How do you handle API rate limiting and request throttling in React projects?

89.   Explain your experience with implementing authentication and authorization using OAuth or OpenID Connect in a React application.

90.   Describe a situation where you had to implement a custom UI component library or design system in a React application.

91.   How do you handle data caching and offline support in React Native mobile applications?

92.   Explain your approach to handling complex data synchronization and conflict resolution in React Native projects.

93.   Describe a scenario where you had to optimize the performance of a React application for low-end devices or slow networks.

94.   How do you handle cross-platform development and code sharing between React and React Native projects?

95.   Explain your experience with implementing push notifications and real-time updates in React Native mobile applications.

96.   Describe a situation where you had to integrate hardware features or device APIs (e.g., camera, GPS) in a React Native application.

97.   How do you handle layout responsiveness and adaptive UI in React Native projects?

98.   Explain your approach to handling offline data storage and synchronization in React Native applications.

99.   Describe a scenario where you had to optimize the startup time and reduce the app size of a React Native mobile application.

100.            How do you handle biometric authentication (e.g., fingerprint, face recognition) in React Native projects?

101.            Explain your experience with integrating third-party native modules or libraries in a React Native application.

102.            Describe a situation where you had to implement deep linking and universal links in a React Native mobile application.

103.            How do you handle cross-platform testing and automated testing in React Native projects?

104.            Explain your approach to handling app updates and version management in React Native applications.

105.            Describe a scenario where you had to implement offline maps or geolocation functionality in a React Native application.

106.            How do you handle in-app purchases and subscription management in React Native projects?

107.            Explain your experience with integrating analytics and crash reporting tools in React Native applications.

108.            Describe a situation where you had to implement real-time collaboration or multiplayer functionality in a React Native application.

109.            How do you handle memory management and performance optimization in React Native projects?

110.            Explain your approach to handling app localization and multi-language support in React Native applications.

111.            Describe a scenario where you had to optimize the performance of a React Native application for different screen sizes and densities.

112.            How do you handle offline media playback and caching in React Native projects?

113.            Explain your experience with integrating social media sharing and login functionality in a React Native application.

114.            Describe a situation where you had to implement background tasks or background synchronization in a React Native mobile application.

115.            How do you handle app security and data protection in React Native projects?

116.            Explain your approach to handling app navigation and routing in React Native applications.

117.            Describe a scenario where you had to implement complex gestures and touch interactions in a React Native application.

118.            How do you handle app theming and customization options in React Native projects?

119.            Explain your experience with integrating augmented reality (AR) or virtual reality (VR) functionality in a React Native application.

120.            Describe a situation where you had to optimize the battery consumption and power efficiency of a React Native mobile application.

121.            How do you handle app performance profiling and optimization in React Native projects?

122.            Explain your approach to handling background synchronization and offline data access in React Native applications.

123.            Describe a scenario where you had to implement audio or video streaming functionality in a React Native application.

124.            How do you handle cross-platform push notifications and real-time updates in React Native projects?

125.            Explain your experience with integrating native navigation libraries (e.g., React Navigation) in a React Native application.

126.            Describe a situation where you had to optimize the memory usage and avoid memory leaks in a React Native mobile application.

127.            How do you handle app localization and RTL (right-to-left) support in React Native projects?

128.            Explain your approach to handling secure storage and encryption of sensitive data in React Native applications.

129.            Describe a scenario where you had to implement custom transitions and animations in a React Native application.

130.            How do you handle app testing and debugging in React Native projects?

131.            Explain your experience with integrating background geolocation and location tracking in a React Native application.

132.            Describe a situation where you had to implement real-time chat or messaging functionality in a React Native application.

133.            How do you handle app distribution and publishing to app stores in React Native projects?

134.            Explain your approach to handling platform-specific code and native module integrations in React Native applications.

135.            Describe a scenario where you had to optimize the network requests and API communication in a React Native mobile application.

136.            How do you handle cross-platform data synchronization and conflict resolution in React Native projects?

137.            Explain your experience with integrating voice recognition or speech-to-text functionality in a React Native application.

138.            Describe a situation where you had to implement background audio playback or audio streaming in a React Native application.

139.            How do you handle app accessibility and assistive technologies support in React Native projects?

140.            Explain your approach to handling cross-platform theming and styling in React Native applications.

141.            Describe a scenario where you had to implement a custom UI component or widget using native code in a React Native application.

142.            How do you handle background image loading and caching in React Native projects?

143.            Explain your experience with integrating biometric authentication (e.g., fingerprint, face recognition) in a React Native application.

144.            Describe a situation where you had to optimize the startup time and reduce the app size of a React Native mobile application.

145.            How do you handle cross-platform localization and multi-language support in React Native projects?

146.            Explain your approach to handling app updates and version management in React Native applications.

147.            Describe a scenario where you had to implement offline maps or geolocation functionality in a React Native application.

148.            How do you handle in-app purchases and subscription management in React Native projects?

149.            Explain your experience with integrating analytics and crash reporting tools in React Native applications.

150.            Describe a situation where you had to implement real-time collaboration or multiplayer functionality in a React Native application.