Question 1

What is the difference between FlatList and ScrollView in React Native?

Accepted Answer

ScrollView renders all its children at once, which is poor for performance with large lists. FlatList lazily renders items as they appear on the screen, making it highly performant for long lists of data.

Question 2

What is the difference between React and React Native?

Accepted Answer

React is a JavaScript library for building web UIs using the DOM. React Native is a framework for building native mobile apps using React; it uses native components (like View and Text) instead of HTML elements (like div and p).

Question 3

How does React Native's New Architecture improve performance?

Accepted Answer

The New Architecture replaces the JSON Bridge with JSI (JavaScript Interface), allowing direct C++ calls between JS and Native threads. It also introduces Fabric (new rendering system) and TurboModules (lazy loading of native modules) for better performance.

Question 4

What is a closure in JavaScript?

Accepted Answer

A closure is a function that retains access to its outer lexical scope even after the outer function has finished executing. It forms a 'closed over' variable environment, commonly used for data encapsulation and callback patterns.

Question 5

How does Node.js handle concurrency despite being single-threaded?

Accepted Answer

Node.js uses an event loop with non-blocking I/O and a libuv thread pool. It offloads I/O operations (file, network) to the OS/thread pool, allowing the single main thread to handle thousands of concurrent connections efficiently.

Vikash Chaurasia