React Native Interview Questions

1.      What is React Native and how is it different from React?

React Native is a framework for building mobile apps using React, whereas React is a JavaScript library for building user interfaces. React Native allows developers to build native mobile apps using the same components and concepts they use in React web development.

2.      What are the advantages of using React Native?

Cross-platform compatibility, ability to use the same codebase for both iOS and Android, ability to use native modules and components, hot-reloading, and a large community and ecosystem.

3.      How does the component lifecycle work in React Native?

React Native components have a lifecycle, similar to React components, with methods that are called at specific points in the component's existence. These include componentDidMount, componentWillUnmount, shouldComponentUpdate, and others.

4.      How do you handle navigation in a React Native app?

There are several libraries available for handling navigation in a React Native app, such as React Navigation and React Native Navigation. These libraries provide a way to navigate between screens, pass data between screens, and handle the navigation stack.

5.      How do you handle different screen sizes and resolutions in a React Native app?

React Native provides the ability to use flexbox layout, which allows for responsive design. Additionally, there are libraries such as react-native-responsive that can be used to handle different screen sizes and resolutions.

6.      How do you handle API calls in a React Native app?

There are several libraries available for handling API calls in a React Native app, such as axios and fetch. These libraries provide a way to make HTTP requests and handle the response.

7.      How do you debug a React Native app?

React Native provides a built-in debugging tool called the JavaScript Debugger. This tool allows you to debug your code in a browser, and also provides the ability to set breakpoints, inspect variables, and more.

8.      What are some common performance issues in React Native and how to solve them?

Some common performance issues in React Native include slow initial load times, slow navigation, and slow rendering. To solve these issues, you can use techniques like lazy loading, code splitting, and minimizing the use of bind in your components.

9.      Explain the concept of Redux in React Native?

Redux is a library that allows you to manage the state of your application in a centralized store. This makes it easier to manage data flow and state updates, and improves the overall performance of the application.

10.   How to create a custom component in React Native?

To create a custom component in React Native, you can define a class that extends the React.Component class. This class should define a render method that returns the JSX for the component. Additionally, you can also define any custom methods and properties for the component.

11.   What are the benefits of using JSX in React Native?

JSX is a syntax extension for JavaScript that allows you to write HTML-like elements in your JavaScript code. It provides a way to create reusable components, and also allows you to use familiar HTML elements when working with the DOM. Additionally, it also allows to use javascript expressions in HTML elements.

12.   How do you handle touch events in React Native?

React Native provides a set of built-in touchable components, such as TouchableOpacity and TouchableHighlight, that you can use to handle touch events. These components accept an onPress prop, which you can use to attach an event handler to the touch event.

13.   How do you handle local storage in React Native?

React Native provides a built-in AsyncStorage module for handling local storage. This module allows you to save and retrieve data from the device's local storage, and also supports basic CRUD operations.

14.   How do you handle form input in React Native?

React Native provides a set of built-in form components, such as TextInput and Picker, that you can use to handle form input. These components can be used in conjunction with a state management library like Redux to manage the form data.

15.   How do you handle device camera access in React Native?

React Native provides a built-in CameraRoll module for handling device camera access. This module allows you to access the device's camera roll and retrieve photos. Additionally, there are third-party libraries such as react-native-camera that can be used to access the device's camera and take pictures.

16.   How to implement Push notifications in React Native?

React Native provides a built-in module for handling push notifications, called PushNotificationIOS for iOS and react-native-push-notification for android. These modules allow you to register for push notifications, handle incoming notifications, and display notifications to the user.

17.   How do you use maps in React Native?

React Native provides a built-in MapView component that can be used to display maps. This component can be customized with various options, such as the map's center and zoom level, and also supports events such as onPress and onRegionChange. There are also third-party libraries such as react-native-maps that provide additional functionality and customization options.

18.   How do you handle cross-platform compatibility in React Native?

React Native provides a built-in Platform module that allows you to detect the current platform (iOS or Android) and write platform-specific code. Additionally, there are libraries such as react-native-platform-specific-styles that make it easier to handle cross-platform compatibility in your styles and layout.

19.   How to use third-party libraries in React Native?

React Native uses npm for managing third-party libraries. You can install a library by running npm install <library-name>. Then you can use the library by importing it in your code and following the library's documentation for usage.

20.   How do you handle offline scenarios in React Native?

React Native provides a built-in NetInfo module that allows you to detect the device's network connection status. Additionally, there are libraries such as redux-offline and offline-first that provide tools for handling offline scenarios, such as storing data locally and synchronizing it with a remote server when the device comes back online.

21.   How do you handle image caching in React Native?

React Native provides a built-in Image component, which can be used to display images. However, it doesn't provide an in-built image caching feature. But we can use libraries such as react-native-cached-image to handle image caching. It allows you to cache images and display them quickly, even when the device is offline.

22.   How do you handle accessibility in React Native?

React Native provides built-in support for accessibility, but it does not provide all the accessibility features out of the box. You can use libraries such as react-native-accessibility to handle accessibility in your app, such as adding accessibility labels, roles and states to your components.

23.   How do you implement i18n and l10n in React Native?

React Native does not provide built-in support for i18n (Internationalization) and l10n (Localization) out of the box. But we can use libraries such as react-native-localize or react-intl to handle i18n and l10n in your app. These libraries provide tools to support multiple languages and formats, such as date and currency formatting.

24.   How do you handle deep linking in React Native?

React Native provides a built-in Linking module that allows you to handle deep linking in your app. This module allows you to open external links, such as web pages, and also allows you to handle incoming links, such as links that are opened from an external app.

25.   How do you handle animations in React Native?

React Native provides a built-in Animated module that allows you to handle animations in your app. This module allows you to create animations and transitions, such as moving elements on the screen, and also provides tools for creating complex animations, such as spring animations and timing animations. Additionally, there are libraries such as react-native-animatable that provide additional animation options and effects.