Mobile Development
React Native Questions Comprehensive guide covering React Native fundamentals, Architecture, Styling, and Component Communication. Each answer is technically rigorous for professional interviews.
1. What is React Native? Beginner 2. How does React Native differ from React? Beginner 3. What are the key features of React Native? Beginner 5. Explain the concept of components in React Native Beginner 6. What is the difference between functional and class components? Intermediate 7. How do you create a new React Native project? Beginner 8. What is the purpose of the AppRegistry? Intermediate 9. What are React Native's core components? Beginner 10. Explain the use of the View component Beginner 11. What is the purpose of the Text component? Beginner 12. What is the purpose of the TouchableOpacity component? Beginner 13. What is the purpose of the SafeAreaView component? Intermediate 14. How do you use images in React Native? Beginner 15. Are all React components usable in React Native? Intermediate 16. What are the differences between React Native CLI and Expo? Intermediate 17. What are the advantages of React Native? Beginner 18. What are the limitations of React Native? Intermediate 19. How is the entire React Native code processed to show final output on a mobile screen? Advanced 20. What is the React Native bridge? Advanced 21. How does React Native communicate with native modules? Advanced 22. What are native modules? Intermediate 23. Describe the role of props in React Native Beginner 24. What are state and lifecycle methods? Beginner 25. What is the difference between props and state? Beginner 26. Explain the concept of 'props drilling' Intermediate 27. How can you avoid props drilling? Intermediate 28. Explain the concept of 'lifting state up' Intermediate 29. What is the significance of the key prop? Intermediate 30. What is the difference between controlled and uncontrolled components? Intermediate 31. How do you handle user input in React Native? Beginner 32. What is the difference between a modal and a popup in React Native? Intermediate 33. What are render props? Advanced 34. How do you style components in React Native? Beginner 35. What are StyleSheet objects? Beginner 36. What is Flexbox, and how is it used in React Native? Beginner 37. How does React Native handle different screen sizes? Intermediate 38. What is the difference between width/height in pixels vs percentages? Intermediate 39. How do you implement theming in a React Native app? Intermediate 40. What are hooks in React Native? Beginner 41. How do you use the useState hook? Beginner 42. What is the useEffect hook used for? Beginner 43. What is the difference between componentDidMount and useEffect? Intermediate 44. Explain the importance of useCallback and useMemo Advanced 45. What is the role of useReducer in state management? Advanced 46. What is useContext hook? Intermediate 47. What is useRef hook? Intermediate 48. What is the dependency array in useEffect? Intermediate 49. How do you cleanup in useEffect? Intermediate 50. What is the purpose of the FlatList component? Beginner 51. What's the difference between ScrollView and FlatList? Beginner 52. When should you use SectionList over FlatList? Intermediate 53. What is the role of the getItemLayout prop in FlatList? Advanced 54. How can you optimize images in a React Native list? Intermediate 55. What is the InteractionManager and how is it used? Advanced 56. How do you implement navigation in React Native? Beginner 57. What is the difference between Stack and Tab Navigator? Beginner 58. How do you pass parameters to a new screen in React Navigation? Intermediate 59. What are the common performance bottlenecks in React Navigation? Advanced 60. What is the role of Redux in React Native? Intermediate 61. When should you use Context API instead of Redux? Intermediate 62. What is Redux Thunk or Saga used for? Advanced 63. What is Zustand and why is it popular? Intermediate 64. What is the purpose of React Query (TanStack Query)? Advanced 65. How do you handle memory leaks in a React Native app? Advanced 66. What are the rules of hooks? Beginner 67. Explain the use of the useReducer hook Intermediate 68. What is the useImperativeHandle hook? Advanced 69. How do you implement a custom hook? Intermediate 70. What is the purpose of React.memo? Intermediate 71. What is the difference between useMemo and useCallback? Advanced 72. What is the purpose of the key prop in lists? Beginner 73. How do you handle gestures in React Native? Intermediate 74. What is the role of the Animated library? Intermediate 75. What is the Hermes engine? Advanced 76. What is the role of AsyncStorage? Beginner 77. What is MMKV storage and why is it faster than AsyncStorage? Advanced 78. What is the difference between SQLite and Realm in React Native? Advanced 79. How do you implement offline storage in React Native? Intermediate 80. How do you perform API calls in React Native? Beginner 81. What is the Fetch API vs Axios? Intermediate 82. How do you handle network security and SSL Pinning? Advanced 83. What is the purpose of the Animated library? Intermediate 84. What is the 'useNativeDriver' prop in animations? Intermediate 85. Explain the use of the react-native-reanimated library. Advanced 86. What is LayoutAnimation? Intermediate 87. What is Lottie for React Native? Intermediate 88. How do you handle error responses from APIs? Intermediate 89. What is retry logic for failed API calls? Advanced 90. What are the challenges of using React Native for complex animations? Advanced 91. How do you manage API versioning in React Native? Intermediate 92. What is the XHR module used for? Advanced 93. How do you handle binary data or file uploads in React Native? Intermediate 94. What is the purpose of the watermelondb library? Advanced 95. Explain the concept of 'optimistic UI updates'. Advanced 96. How do you implement custom animations in React Native? Intermediate 97. What is the difference between Animated.timing and Animated.spring? Beginner 98. How do you store data in AsyncStorage safely? Beginner 99. What is the significance of the storage system in React Native? Beginner 100. How do you handle API calls in a performant way? Intermediate 101. How do you debug a React Native application? Beginner 102. What is Flipper and how does it help in development? Intermediate 103. How can you test React Native components? Intermediate 104. What is the difference between Jest and Detox? Advanced 105. How do you implement Error Boundaries in React Native? Advanced 106. What is the significance of the PureComponent vs React.memo? Intermediate 107. Explain the concept of Higher-Order Components (HOCs). Intermediate 108. What is the 'render prop' pattern? Advanced 109. What is the 'compound component' pattern? Advanced 110. What is forwardRef and when should you use it? Intermediate 111. How do you handle conditional rendering in React Native? Beginner 112. What is the use of react-native-vector-icons? Beginner 113. Explain setNativeProps and why it is used. Expert 114. What are the common strategies for effective logging in production? Intermediate 115. Discuss the challenges of testing components with external dependencies. Advanced 116. What is the role of code reviews in React Native development? Beginner 117. What is the difference between unit testing and integration testing? Intermediate 118. What are Snapshot Tests in Jest? Beginner 119. How do you test a component that uses a Hook like useEffect? Advanced 120. What is the benefit of using React Native Testing Library over Enzyme? Intermediate 121. How do you debug network requests in React Native? Beginner 122. What is the purpose of the 'shouldComponentUpdate' lifecycle method? Intermediate 123. Describe Timers in a React Native application. Beginner 124. What is the difference between setTimeout and setImmediate? Advanced 125. How do you handle touch events in React Native? Intermediate 126. What are the differences between native modules and JavaScript modules? Intermediate 127. How do you create a native module? Advanced 128. What is the React Native Bridge and why is it being replaced? Advanced 129. What is JSI (JavaScript Interface)? Expert 130. What are TurboModules? Expert 131. What is Fabric architecture? Expert 132. How do you integrate React Native into an existing Android or iOS app? Advanced 133. How do you implement push notifications in React Native? Intermediate 134. What is the difference between remote and local notifications? Beginner 135. How do you implement deep linking in a React Native app? Intermediate 136. What are Universal Links (iOS) and App Links (Android)? Advanced 137. How do you handle notifications when the app is in the background vs. quit state? Advanced 138. What is Firebase Cloud Messaging (FCM)? Beginner 139. How do you use environment variables in React Native? Intermediate 140. What is the Metro bundler? Intermediate 141. What is the difference between Fast Refresh and Hot Reloading? Beginner 142. How do you set up different environments (dev, staging, prod)? Advanced 143. What is the purpose of the react-native-config library? Intermediate 144. What is a 'flavor' in Android and a 'scheme' in iOS? Advanced 145. Discuss the advantages of using native components in a React Native app. Advanced 146. How do you secure API keys in React Native? Advanced 147. What is the difference between development and production builds? Beginner 148. How do you handle user permissions in React Native? Intermediate 149. What is the 'Info.plist' file in iOS? Beginner 150. What is the 'AndroidManifest.xml' in Android? Beginner 151. How do you use TypeScript in React Native? Beginner 152. What are the benefits of using TypeScript over plain JavaScript? Beginner 153. How do you type props and state in a functional component? Intermediate 154. What is the difference between 'type' and 'interface' in TypeScript? Intermediate 155. What are Generic Types and how are they useful in React Native? Advanced 156. How do you use Firebase in React Native? Intermediate 157. What is the difference between Firestore and Realtime Database? Intermediate 158. What is Firebase Authentication? Beginner 159. What is Firebase Crashlytics and why is it important? Beginner 160. How do you secure sensitive data like API keys in a mobile app? Advanced 161. What is Code Obfuscation and how do you implement it? Advanced 162. What is SSL Pinning and why is it used? Advanced 163. How do you handle Right-to-Left (RTL) languages in React Native? Intermediate 164. What is the 'i18next' library and how is it used? Intermediate 165. What is the role of react-native-localize? Intermediate 166. How do you handle permissions in React Native? Intermediate 167. What is the 'Keychain' on iOS and 'Keystore' on Android? Advanced 168. How do you implement biometric authentication (FaceID/Fingerprint)? Intermediate 169. What is a Content Security Policy (CSP) in mobile apps? Advanced 170. How do you handle localization of images? Intermediate 171. What is 'Declaration Merging' in TypeScript? Advanced 172. What is Firebase Analytics? Beginner 173. How do you implement 'Dark Mode' using TypeScript and Context? Intermediate 174. What are 'Union Types' and how do they help in API handling? Intermediate 175. How do you handle timezones in a global React Native app? Intermediate 176. How do you build a React Native app for production? Beginner 177. What is the difference between debug and release builds? Beginner 178. How do you generate an APK vs an AAB in Android? Intermediate 179. How do you generate an IPA for iOS? Intermediate 180. What is App Signing and why is it required? Advanced 181. How do you implement a CI/CD pipeline for a React Native app? Advanced 182. What is CodePush and how does it work? Advanced 183. What are Over-the-Air (OTA) updates? Intermediate 184. What is Fastlane? Advanced 185. How do you manage Provisioning Profiles and Certificates in iOS? Advanced 186. What is TestFlight and Google Play Internal Testing? Beginner 187. How do you handle App Store rejections? Intermediate 188. What is the difference between an Ad Hoc and App Store distribution? Advanced 189. What is ProGuard and R8 in Android? Advanced 190. How do you implement Multi-Dex in Android? Expert 191. What is the purpose of the 'Scheme' in Xcode? Intermediate 192. How do you use 'App Center' for distribution? Beginner 193. What is the importance of the Bundle Identifier and Package Name? Beginner 194. How do you handle 'Privacy Manifests' (iOS 17+)? Expert 195. What is the role of 'Version Number' vs 'Build Number'? Beginner 196. What is 'Keystore' and how do you protect it? Intermediate 197. How do you automate App Store screenshots? Advanced 198. What is the difference between 'Internal,' 'Alpha,' and 'Beta' tracks in Google Play? Beginner 199. What is 'App Store Connect'? Beginner 200. What is the 'Google Play Console'? Beginner 201. How do you architect a large-scale React Native application? Expert 202. What are the best practices for handling large datasets in React Native? Advanced 203. How do you set up a monorepo for React Native using NX or Turborepo? Expert 204. What is the importance of accessibility (A11y) in React Native? Intermediate 205. What is your experience with using Hermes? How do you enable it? Advanced 206. Discuss the differences between iOS and Android development in React Native. Intermediate 207. How do you implement a splash screen correctly in React Native? Intermediate 208. What is react-native-svg and when should you use it? Intermediate 209. How do you handle backward compatibility in your applications? Advanced 210. What are the common pitfalls when using third-party libraries? Intermediate 211. How do you ensure data consistency across multiple screens? Intermediate 212. What future trends do you see for React Native? Advanced 213. How do you manage user sessions and authentication tokens securely? Advanced 214. What is the difference between React Native Paper and NativeBase? Intermediate 215. How do you implement a loading spinner using ActivityIndicator? Beginner 216. How do you handle the hardware Back Button in Android? Intermediate 217. What is 'Code Splitting' in a React Native context? Expert 218. How do you optimize app startup time (TTI)? Advanced 219. What is the 'Shadow Thread' and what is its role? Advanced 220. How do you handle 'Zombie' timers and intervals? Intermediate 221. What is the difference between 'px', 'dp', and 'pt' in React Native? Intermediate 222. Explain 'Fabric's' approach to 'Synchronous UI' updates. Expert 223. How do you manage deep links when the app is already open? Intermediate 224. What is the 'Headless JS' task used for? Advanced 225. What is the role of 'ProGuard' in the release build? Advanced 226. How do you handle 'Keyboard Overlapping' in React Native? Beginner 227. What is 'Tree Shaking' and does Metro support it? Advanced 228. How do you manage large binary files in a React Native project? Intermediate 229. What is the difference between 'React Native Link' and 'Autolinking'? Beginner 230. How do you handle image caching in React Native? Intermediate 231. Explain the use of 'ViewabilityConfig' in FlatList. Advanced 232. What is the purpose of the 'reselect' library in Redux? Advanced 233. How do you optimize React Native for 'Low-End' devices? Advanced 234. What is the role of the 'Codegen' tool in the New Architecture? Expert 235. How do you implement 'Pull to Refresh' in a ScrollView? Beginner 236. What is the 'Pressable' component and why is it better than 'TouchableOpacity'? Intermediate 237. How do you handle 'App State' (Foreground/Background)? Intermediate 238. What is the significance of the 'useWindowDimensions' hook? Beginner 239. How do you implement 'Infinite Scrolling'? Intermediate 240. What are 'Sticky Headers' and how do you enable them? Beginner 241. How do you handle user authentication in a React Native app? Intermediate 242. What are the best practices for handling user sessions? Advanced 243. What is NativeBase? Intermediate 244. What is React Native Elements? Beginner 245. How do you implement a loading spinner? Beginner 246. What is the purpose of ActivityIndicator? Beginner 247. How do you handle backward navigation? Beginner 248. What is the BackHandler API? Intermediate 249. What is the 'FlashList' library by Shopify? Advanced 250. How do you implement 'Dark Mode' support effectively? Intermediate