React Native Interview Questions and Answers

Ques 1. How does React Native achieve cross-platform functionality?

React Native achieves cross-platform functionality by allowing developers to write components in JavaScript and then rendering them using native components for each platform.

Ques 2. Explain the purpose of 'state' in React Native.

State in React Native is a way to manage the internal state of a component. It represents the data that can change over time and influences the rendering of the component.

Example:

const [count, setCount] = useState(0);

Ques 3. Explain the React Native component lifecycle.

The React Native component lifecycle consists of several phases such as mounting, updating, and unmounting. Key methods include componentDidMount, componentDidUpdate, and componentWillUnmount.

Ques 4. What is the role of 'FlatList' in React Native?

'FlatList' is a component in React Native used for efficiently rendering a scrolling list of data. It only renders the components that are currently in view.

Example:

  data={data}
  renderItem={({ item }) => {item.title}}
/>

Ques 5. How do you handle navigation in React Native?

React Navigation is a popular library for handling navigation in React Native. It provides a navigation structure that allows developers to navigate between screens in a React Native app.

Ques 6. What is the purpose of 'AsyncStorage' in React Native?

'AsyncStorage' is a simple, asynchronous, key-value storage system in React Native. It is used for storing small amounts of data persistently across app restarts.

Example:

import AsyncStorage from '@react-native-async-storage/async-storage';

AsyncStorage.setItem('key', 'value');

Ques 7. What are Hooks in React Native?

Hooks are functions that allow developers to use state and other React features in functional components. Common hooks include useState and useEffect.

Example:

const [count, setCount] = useState(0);

useEffect(() => {
  console.log('Component mounted!');
}, []);

Ques 8. How does React Native handle platform-specific code?

React Native uses platform-specific file extensions (e.g., .ios.js and .android.js) to include platform-specific code. This allows developers to write code that targets specific platforms.

Ques 9. Explain the concept of 'Flexbox' in React Native.

Flexbox is a layout model in React Native that allows components to be dynamically arranged in a container, either horizontally or vertically, to accommodate different screen sizes.

Example:

Ques 10. How can you integrate third-party libraries in a React Native project?

Third-party libraries in React Native can be integrated using tools like npm or yarn. Developers typically install the library and link it to the project using react-native link.

Example:

npm install react-navigation

# After installation, link the library
react-native link react-navigation

Ques 11. How can you debug a React Native application?

React Native applications can be debugged using tools like React DevTools, Chrome DevTools, and the built-in debugging tools provided by React Native CLI. 'console.log' is also commonly used for debugging.

Ques 12. Explain the purpose of the 'Linking' module in React Native.

The 'Linking' module in React Native is used for deep linking and opening external URLs. It allows developers to interact with the app's navigation and handle incoming URL schemes.

Ques 13. How can you handle forms in React Native?

Forms in React Native can be handled using state to manage form data, controlled components, and event handlers. Libraries like 'Formik' and 'React Hook Form' can also be used for form management.