Top React Native Interview Questions for Job Seekers

When developers develop applications, they need to store information permanently for an application. The react native applications use the database to remember all the information which is related to the applications and their respective users. React Native uses AsyncStorage for data storing purpose. AsyncStorage is a simple, unencrypted synchronous, persistent, key-value storage system that is global to the application. On iOS, AsyncStorage is backed by native code that stores small values in the serialized dictionary and large values in separate files. On Android, AsyncStorage will use either RocksDB or SQLite based on which is available.

Four steps are needed to understand how to use AsyncStorage to React Native-

• Don’t need to install any extra library. By default, it comes with React Native. Import {AsyncStorage} from 'react-native';
• AsyncStorage uses key-value pairs for saving the data for example- AsyncStorage.setItem ('myKey', myValue);
• To load the saved data run given the command- AsyncStorage.getItem('myKey'). then((myValue)=> {this.setState ({'myKey': myValue});});
• Since loading data is a time-consuming task, it is designed to be an asynchronous operation. So getItem returned the promise, which will invoke the call back function when the read operation is completed.

React Native gives the Fetch API which offers networking needs. React Native makes use of componentDidMount lifecycle method to load the records from server.
fetch('https://bestinterviewquestion.com/menu.json')

Here are some of the advantages of native apps over hybrid apps:

• Native app development has fewer dependencies for bugs to occur.
• In the native app, you are not relying on cross-platform tools.
• The processing speed of the native app is faster than the hybrid app.
• It provides great designs and user experience than a hybrid app.

Hooks are a new enhancement in React 16.8. They allow to utilize the state and other react features without involving the class. The major agenda behind using the hooks are to handle the side effects in the functional components of react.

Fabric is the latest architecture of React Native which has been proposed by the company to develop the close and better user experience of mobile apps than the native apps.

React Component: A class or function which optionally accepts inputs and returns a React element via JSX.

React Element: It describes what the user wants to be displayed on the screen, Simplifying it, the react element is an object representation for some UI.

Yes, it’s entirely possible. App developers use the same code base for iOS and Android as Reacts entirely takes care of the native components translations part. For example, a React Native ScrollView uses ScrollView on Android and native UiScrollView on IOS.

The React Native has following limitations or cons

• Security risks
• Single threaded interface
• Poor memory management
• Doesn’t support all native APIs
• Dependable on third-party libraries
• Not equivalent to true native apps written entirely on Java or Swift/Obj-C.