React Native Interview questions

React Native Interview questions | Freshers & Experienced

  • Calvin
  • 02nd Dec, 2019
  • 498 Followers

React Native Interview Questions

Q1. What is React Native?

React Native is a framework of Javascript. This is used to write real code for natively providing mobile applications for android and iOS. This framework as the name depicts is based on React which is the Javascript library of Facebook for developing user interfaces, the difference is that it targets the mobile applications and not the browsers. Therefore, web developers are now able to code mobile applications that will feel and look truly native.

Q2. Enlist few advantages of React Native?

Some of the advantages of React Native are that it is quite easy to develop mobile applications with the help of this. It has strong development tools the error messages are meaningful as well. Another benefits or advantages of React Native include the code reusability feature and knowledge feature. It lets the developers iterate faster, along with sharing knowledge as well as resources more efficiently. And moreover, apart from the knowledge it also allows sharing the code.

Q3. What are most prominant features of React Native?

Mentioned below are the features of React Native:

  • Need to write only a single time but can be used everywhere
  • It focuses entirely on the user interface. That is to say, it is greatly responsive as well.
  • The Development Time in React Native is quite beneficial for developers to work.
  • React Native immensely renders support for third-party libraries.
  • React Native uses the programming language - Javascript. It is quite popular and used widely.

Q4. What type of applications we can create with React Native?

React Native is a JavaScript framework for creating native mobile applications for Android and iOS. It is based on Facebook’s JavaScript React library, but it targets the mobile platforms instead of the browser. React Native builds production-ready cross-platform applications that actually renders using the standard rendering API from the host platform.

Q5. List few popular apps created with React Native?

Some of the popular applications created with React Native are,

  • Facebook
  • Instagram
  • Skype
  • Pinterest
  • Uber
  • Tesla
  • Discord
  • Tencent
  • Baidu Mobile
  • Sound Cloud
  • Vogue
  • Salesforce
  • Bloomberg

Q6. In which language React Native is written?

React Native is based on the React JS which is written in JavaScript. So most of the React Native is written in JavaScript among other languages such as Java, C++, Python, and Objective-C.

Q7. How to install React Native using NPM?

To install react native using npm, first make sure that you have npm installed on your system. Then, use the following command to install the react-native. > npm i react-native

Q8. Write a code to create Hello World app in React Native?

The code for the Hello World application in the React Native is,

import React, { Component } from 'react';
import { Text, View } from 'react-native';
export default class HelloWorldApp extends Component {
  render() {
    return (
      <View style={{ flex: 1, justifyContent: "center", alignItems: "center" }}>
        <Text>Hello, world!</Text>
      </View>
    );}}

Q9. What are Components in React Native?

A component in React Native is a very basic element. It is a portion or part of an application that performs a specific functionality. We can divide our large React Native application into many small Components.

The major components in React Native are mentioned below:

  • View: It is in-built and used to display content.
  • State: It is a mutable data type.
  • Props: This is an immutable type of data. This is used to pass data among different components.
  • Style: Styling is one of the most important things in web or mobile application development. It makes the application attractive.
  • Flex Layout: This component is provided to render a clean layout. Flexbox is used to specify the children of the component layout.

Q10. Explain props in React Native?

The properties of the React Native components are called props. The props are the parameters that are used to customize different components of the React Native at the time of the creation. These parameters are immutable as they cannot be changed.

You can use the props in your own components. A good example of a prop is the source property of the Image component in the React Native.

Q11. Explain Animations in React Native?

Animations in the React Native are a way to create a good user experience. It makes the objects move and have momentum. The animation library is used to create animations on the objects. It makes the animations fluid, powerful, while also making the process painless and easy to maintain. This library focuses on the relationship between input and output to configure the animation transformation in between.

Q12. What are Native Modules in React Native?

A Native Module is a set of JavaScript functions that are used to provide native capabilities when developing applications. These modules are implemented for each platform (iOS and Android) and provide the native capabilities when the React Native doesn’t have a corresponding module.

Q13. How to setup a Native Module in React Native?

The create-react-native-module tool is used to set up the basic structure for the native module. It is a third-party tool and it creates the native library module in a single command.

//usage
$ create-react-native-module MyLibrary

The above command creates a folder named MyLibrary where the library is created. After creating a library, you should run the npm install command to install dependencies in the newly created library.

Q14. Explain Gesture Responder System?

The Gesture responder system is the internal system of React Native. This system manages the lifecycle of various gestures in the system. As it is important to know what the user wishes to do inside the application, touch, swipe, scroll or something else. The system was first implemented for this and many other reasons. Moreover, one can make use of it to understand clearly what the user wishes to do inside the application.

Q15. What are different types of views are avaible in React Native?

A view is used to create an interface in the React Native. It is one of the most important components in the React Native. The view in the React Native can map directly to the native view on different platforms such as UIView, <div>, and android.view.

Q16. What is React Navigation?

The React Navigation is used to provide navigation on both the iOS and Android React Native applications. It is platform-specific and easy to use in the library. It is also easily customizable in any part and can be extended at any layer.

Q17. Which Runtime environment React Native uses?

React Native uses JavaScriptCore, the JavaScript engine as the runtime environment for executing the JavaScript code.

Q18. How to enable Fast Refresh in React Native?

The Fast Refresh is used to get near-instant feedback for changes that you make in the React components. This feature is enabled by default. Or you can toggle the “Enable Fast Refresh” in the React Native developer menu to start using this feature to see the edits within a second or two.

Q19. How to display static resource like an image in React Native?

React Native provides a common way to manage the static resources like the image in your Android and iOS apps. You can add the resource in the source code tree and reference the source using the Image tag.

//example
<Image source={require(‘./image.png’)} />

Q20. What is WebView? How to use WebView in React Native?

The WebView in the React Native is used to render a web page in your mobile application. To use it, you have to first import the WebView into your component.

//example of using WebView
import React, { Component } from 'react';
import { WebView } from 'react-native-webview';
class MyWeb extends Component {
  render() {
    return (
      <WebView
        source={{ uri: 'https://infinite.red' }}
        style={{ marginTop: 20 }}
      />
    );
  }
}

About Author :

  • Author of React Native Interview questions

    Calvin Carlo

    Calvin is a Senior web developer, a Javascript enthusiast, and a technical writer. He is very interested in learning new technologies and writing technical blogs on It. He loves playing Cricket, watching Hollywood action movies and is big fan of Michael Douglas.

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