AFour Technologies Java Developer Interview Questions and Answers

Sqlite database can be implemented in React Native using 'react-native-sqlite-storage' package.

• Install 'react-native-sqlite-storage' package using npm.

• Import SQLite from 'react-native-sqlite-storage'.

• Create a database using SQLite.openDatabase() method.

• Execute SQL queries using executeSql() method.

• Close the database connection using close() method.

Generator functions are functions that can be paused and resumed, allowing for lazy evaluation of data.

• Generator functions use the yield keyword to pause execution and return a value.

• They can be used to generate an infinite sequence of values.

• They are memory efficient as they only generate values when needed.

• Example: function* myGenerator() { yield 1; yield 2; yield 3; }

• Example: const infiniteGenerator = function*() {

Push notifications can be implemented in Android and iOS using Firebase Cloud Messaging (FCM) and Apple Push Notification service (APNs) respectively.

• For Android, integrate FCM SDK in the app and use FCM console to send notifications.

• For iOS, create an APNs certificate, configure the app to receive notifications, and use APNs to send notifications.

• Both platforms require handling of notification payload in the app to di...read more

I used React Native for my last app.

• Developed UI components using React Native

• Integrated APIs to fetch and display data

• Implemented Redux for state management

• Used Firebase for authentication and database

• Optimized app performance using React Native Debugger

Functional components are stateless and return UI elements based on input props, while non-functional components have state and can change UI based on user interaction.

• Functional components are simpler and easier to test than non-functional components.

• Non-functional components can have state and lifecycle methods, while functional components cannot.

• Examples of functional components include buttons, labels, and icons, w...read more