Top React Native Interview Questions for Job Seekers
React Native is one of the most popular mobile application frameworks developed by Facebook and is based on JavaScript. This framework is growing so fast in the market that it is used by more than 8000 companies and these companies include names like Facebook, Instagram, Airbnb, etc. To be a part of these companies could be a dream for anyone and to achieve this dream you have to be a React developer. Collectively, we have prepared a list of React Native Interview Questions and Answers, by going through these interview questions you could get what you are thinking of. 70% of companies consider React Native to build applications as it is faster in development and deployment time.
Top 10 React Native Interview Questions for 2023
- What is the purpose of a Native module in React Native, and how do you create one?
- How does React Native handle layout and styling compared to CSS?
- How do you debug a React Native application?
- What is the difference between AsyncStorage and LocalStorage in React Native?
- How do you handle navigation between screens in a React Native application?
- Can you explain the concept of React Native bridge and how it works?
- What is the purpose of React Native's "Flexbox" layout, and how does it work?
- How do you handle errors in a React Native application, and what are some best practices?
- Can you explain the "Props drilling" concept in React Native and how you avoid it?
- How do you handle user authentication and authorization in a React Native application?
- Can you explain the concept of Redux-saga and how it works with Redux in React Native?
- How do you test a React Native application, and what are some best practices?
| Quick Facts About React Native | |
|---|---|
| When did React Native Initial release? | 26th March 2015 |
| What is the latest version of React Native? | React Native 0.70 was released on Sep 5, 2022 |
| React Native is Created By | |
| What language does React Native use? | It is based on React js, which is written in JavaScript. |
React Native Technical Interview Questions and Answers
It is important to upgrade the existing react-native to the latest version in order to access more featural aspects that involve views, APIs, classes, arrow functions, template string, import and export modules, array destructing and development tools.
Following steps should need to be performed to update the react-native to the latest version:
- Update react native, react and Expo package versions for upgrading the expo projects in package.json
- Install the latest SDK version which is compatible with the latest version of react-native in the app.json file.
- Upgrade React Native CLI using the command:
react-native upgrade - Install upgrade helper web tool for upgrading the applications
- Upgrade existing file using the command
react-native init - Perform troubleshoot activity to upgrade with react native CLI
React Native 0.61 is the latest version of react native which is proficiently able to optimize the features of react-native version 0.60. the latest version of react-native comes with the latest and improved features.
The react native version 0.61 is incorporated with four advanced level features such as:
- React native 0.61 is provided with improved CocoaPods Support
- For dimension updates, new useWindowDimensions Hook feature is provided
- Fest processing and refreshing of the application
- React native is upgraded to 16.9 as it opposes old names for unsafe methods
With the help of Axios, the user can send GET, POST, PUT, and DELETE requests to the REST API and render a response to the application. With the help of Axios, users can interact with the REST API. In general, Axios is a promise-based HTTP client which used by the react-native.
Axios is associated with a number of features which are enlisted below:
- It makes XMLHttpRequests from the browser
- From react native framework, it makes Http requests
- It supports react-native API’s
- It provides a client-side feature that protects the application from XSRF.
- It automatically transforms response and request data.
How to use Axios
- You have to install Axios using npm
npm install axios - After that you have to import this module.
import axios from 'axios';
Using POST method.
axios.post('/login', {
username: 'bestinterviewquestion',
password: 'admin@123'
})
.then(function (response) {
console.log(response);
})
.catch(function (error) {
console.log(error);
});
| Controlled Components | Uncontrolled Components |
|---|---|
| A controlled component is one that is bound to a value, and the changes inside it will be handled in code by using event-based callbacks. | This is similar to the traditional HTML form inputs, but, here, the form data is handled by the DOM itself. |
| It does not maintain its internal state. | It maintains its internal states. |
| Data is controlled by the parent component. | Here, the data is controlled by the DOM itself. |
| It accepts the current value as a prop. | A ref is used for their current values. |
| Has much efficient control over the form elements and data. | Has less control over the form elements and the data. |
Firebase is a mobile platform that helps you quickly develop high-quality apps, grow your user base and earn more money. This is a tool and infrastructure that users need to build better apps and grow a successful business. In addition, firebase is made up of a complementary feature that users can mix-and-match to fit your needs. There are total give key features of firebase namely authentication, Realtime database, cloud messaging, crash reporting and analytics.
Getting started with firebase by using following steps-
- Create a firebase project in the Firebase console
- Retrieve apikey, authDomian, DatabaseURL and storage bucket from firebase console
- Create a new react-native project
- Install firebase from npm
- Add it into the react-native project
npm install -g react-native-cli
When a developer is working on a project and wants to maintain the project for a long period of time then the user should need TypeScript. In order to use the TypeScript user should need to configure the TypeScript because it gives an option to configure the compiler. Moreover, users can configure the TypeScript as per their requirements and can effectively prioritize the type of errors. Given below are the steps that will enable the developer to use TypeScript in react native-
- Creating a project in react native using-
react-native init myapp --template typescript && node myapp/setup.js && cd myapp - Set up and configure TSlint
npm install --save-dev tslint tslint-eslint-rules tslint-react tslint-config-prettier - Setting up Jest
npm install --save-dev ts-jest - Setting up an enzyme
npm install --save-dev enzyme enzyme-adapter-react-16 react-dom @types/enzyme @types/enzyme-adapter-react-16 - Setting up a test library of react-native
npm install --save-dev react-native-testing-library
Here you will discover a list of fundamental instructions to start creating iOS and Android apps the use of React Native.
react-native init PROJECTNAME
react-native run-android
react-native run-ios
watchman watch-del-all
react-native link LIBRARYNAME
React Native is better than native because of React native as it is a faster framework and allows the developers to create mobile applications that further support iOS and Android. The react native increases the speed of mobile development effectively and it is quite easier for the developers to maintain the mobile applications which are developed to react-native. It is easier for the developer to identify the bug in the applications which are developed in react native.
Gesture Responder System is a system that manages the lifecycle of the applications which are built in React- Native framework. The applications automatically determine the intention of the users through touch. For example, the application determines slide on the widget, touch is scrolling or tapping. The Gesture Responder System allows the components to negotiate these touch interactions without integrating any sought of knowledge regarding their parent component and child component. React Native gesture responder system is the most powerful system, as it uses standard library to detect gestures such as scroll distance, single tap, double-tap, single tap confirmed and pinch distance.
In the end, we know an interview that has a Javascript word in it, is not very easy to crack. By going through various questions published on different websites wouldn’t open the door for you. Here are some bonus tips for you which you should also keep in mind-
- Pick a programming language and make a good command of it.
- Don’t mix concepts of ReactJS with React Native.
- Practice regularly some coding challenges and mock interviews.
- You should know different methods to solve a problem.
- Take time to think before answering, don’t hurry.