React Native Interview Questions

As we are living in the digitized world, every individual is now into mobile phones; there is a vast development in mobile applications and frameworks. React Native is also one of the platforms, a Javascript framework that is used to develop mobile applications on IoS and Android. As mobile applications are having a higher response than the desktop, most organizations are involved in the development of mobile applications based on client requirements.

In this article, you can go through the set of React Native interview questions most frequently asked in the interview panel. And these questions will help you crack the interview as the topmost industry experts curate these questions.

React Native Interview Questions and Answers:

  1. What do you know about React Native? Why is React Native used in the current era of living?

Ans: React Native is one of the open-source platforms, a JavaScript framework specifically designed for building cross-platform mobile applications. React Native is one of the platforms that allow the building of applications with the same design principles available in the JS framework. The React Native applications are usually written in web Technology. The react Native makes use of the fundamental UI building blocks as the Android applications, and the IOS applications are created from an app built using the objective C or Java.
React-native is currently used because of the following reasons:

1. React Native allows a web developer to build mobile applications with JavaScript.

2. The developers working with react Native do not need complete knowledge of the programming languages like Java to develop an Android application.

3. React native provides the flexibility to share the code as most of the code can be shared between the Android and IOS applications.

4. It is responsible for building applications faster as it has the reloading functionality which does not require compilation again and again on making changes.

5. Also provide flexibility if the features are much faster on both the major platforms like Android and iOS applications.

2. Explain briefly how the virtual DOM works with any react native?

Ans: React Native provides the flexibility to create an in-memory data structure cache that is responsible for computing the resulting references and then provide the update to the browsers displayed and efficiently. The DOM also helps developers to be alert to write the code as if the entire page is rendered on each change wherein the react libraries are responsible for generating the sub-components that change.

3. Do you know how to get geolocation in react native?

Ans: React-native uses the geolocation application programming interface, which is an extension of the web spec of the geolocation, whereas, in Android, the new location utilizes the Android. location. API.
Some alternative libraries are used to include the location services API to React Native. They are:

1.React-native-geolocation-service

2.React-native-location

In order to request location access, you will need to use the following inside the application’s AndroidManifest.xml file.
<uses-permission android:name=”android.permission.ACCESS_FINE_LOCATION”/>
<uses-permission

4. Give a brief idea about props in react native?

Ans: There are different crops of various component instances in react native. They will issue the value of the props to render the views. Props are also referred to as properties. A parent component is responsible for passing a prop with the child component. The child components utilize the values that are defined in the props. With the use of these props, it makes it easier to implement the reusable code or reusable program code quickly.

5. Give a brief idea about State in React Native?

Ans: A component called state is used to handle any data that is changeable. State here refers to the change or difference in a component. Each component includes different state values based on which the UI also can be changed.

6. Is it possible to combine the native IOS or Android iOS in react native?
Ans: Yes, it is possible to combine the native iOS or the Android iOS in react native. React native provides the flexibility to connect the components written in different programming languages like Java, Objective C, or swift.
 
7. Give a brief idea about the steps to be followed to create and start to React Native application?
Ans:  The following are the steps to be followed to create and start the React Native application. 

1. The primary step is to install the React Native app using the below command:npm install -g create-react-native-app 
2. The next step is to create a project named NewProject using the command: create-react-native-app NewProject 
3. cd NewProject 

4. npm start

8. Do you know what is the use of WebView in react native?

Ans: WebView is referred to as a component in React Native that is responsible for loading the web page or web content. It is usually imported from the core of the React Native library and can be replaced from the input for React Native. In simple words, webView is referred to as a bridge that helps in connecting the platforms with the react native and provides the user different options to create the connections to an application that is running on the web. It also helps in controlling the navigation and loading an application into the web page. Hence WebView is one of the elements that is helpful and does not require any installation or configuration.

9. List out the different native events available in react-native?
Ans: The following are the different native events available in react native. 

1. Transition events 
2. Keyboard events 
3. Composition events 
4. Form events 
5. Focus events 
6. Pointer-events 
7. Image events 
8. Animation events 
9. Selection events 
10. UI events 
11. Touch events 
12. Wheel events 
13. Media events 

14. Other events

10. What is meant by JavaScriptCore? Which function is used to pass a value between screen in react native?
Ans:  JavaScriptCore is referred to as an open-source web browser engine that provides extensible support for the developers to create their browsers. Javascriptcore runs in WebKit. The function of this.props.navigation. navigate() is used to pass the value between the screen in react native. Below is the syntax.

Syntax: this.props.navigation.navigate(‘RouteName’, { /* params go here */ })

11. What do you know about react native applications? 

Ans: React Native Applications are referred to as the type of applications that are running on mobile devices but will not load over the browser. React Native applications are not web applications. Also, they are not hybrid apps that can run over the WebView component. They are the apps that are built-in single language JavaScript with native components to run on different mobile devices.

12.Briefly explain the differences between React and React Native? 

Ans: The following are the major differences between React and React Native. 

1. React Native is a JavaScript framework that is based on react, while react is a JavaScript library. 

2. React and react native; both of them allow the tags to be used differently in both platforms. 

3. React Native is used to creating cross platform mobile applications while react used for developing the UI and web applications.

13. Give a brief idea about the functionality of StyleSheet.create? 

Ans: The StyleSheet.create() in react native helps in ensuring that the values are Opaque and immutable. They are specifically used to send the style only once through the bridge to avoid passing a new style object.

14. What is ListView? What are the best UI components for React Native? 

Ans: List view is referred to as the core component of react-native which usually contains a list of the items and displays in a vertically scrollable list. 

The best UI components for React Native are listed below: 

1. Ant design 

2. Material UI 

3. Semantic UI 

4. React toolbox 

5. React Bootstrap

15.What do you know about gesture responder systems in react native? 

Ans: Gesture response system is referred to as an integral system of React Native, that is responsible for the management of the lifecycle of gestures in the system. React native is providing its extensible support by involving several different types of gestures to the users. The gestures include zooming, sliding, swiping, tapping. The response to the system is usually used with the animated API and is also responsible for creating the Irreversible gestures.

16. What are the different ways to write React components? 

Ans: There are two different ways of writing react components. They are: 

1. Functional component: Functional component refers to a simple function that returns the JSX. 

2. Cloud-based component: The cloud-based component implements the lifecycle method which returns JSX. It is used as the class keyword.

17. What do you understand about flatlist in react native? 

Ans: Flatlist in React Native to the component that helps in displaying the content in similarly structured data as a scrollable list. It is responsible for handling the final list of data where the number of list items changes dynamically over time.

18. Briefly explain the use of the React Native platform module to React Native? 

Ans: React native platform module is responsible for detecting the platform of the device in which react application is actually running. The below code is used for detecting the platform in react native. 

import {Platform, StyleSheet} from ‘react-native’;

const styles = StyleSheet.create({

  height: Platform.OS === ‘ios’ ? 200 : 100,

});

19.What do you know about flexbox in react native? 

Ans: Flexbox in react native is similar to the work done in CSS on the web. It has additional two exceptions, but it is also possible to provide a consistent layout on the different screen sizes.

20. List some of the users of React Native? 

Ans: There are thousands of react-native building applications that are available in the market. Some of the users who use react native apps are listed here. 

1. Facebook 

2. Instagram 

3. Facebook ads manager 

3. F8 

5. Skype 

6. Bloomberg 

7. Myntra 

8. UberEats 

9. Tesla

Conclusion:

React Native platform is reaching a higher extent in the current technology and advancement, with its high performance in the organizations and the digitized world. As we are living in the world of mobile applications where individuals are too involved and dependent on mobile applications for any type of work. Hence, there is a high demand for mobile applications in this world. This would increase the opportunities for the development of the applications, allowing the organizations to look for individuals to develop the same. Hence, the organizations and the management are looking for experts or individuals who have the knowledge about different frameworks like React Native which would bring them success along with customer satisfaction. The above questions will definitely help you to crack the interview and help you in developing a good career.

 
 
 

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