Question 1

Why is FlatList a much better choice than ScrollView for long lists in React Native?

Accepted Answer

FlatList uses lazy loading and virtualization to recycle only visible items, whereas ScrollView renders and holds all list items in memory at once.

Question 2

What are the key FlatList performance settings (such as windowSize, initialNumToRender, and getItemLayout)?

Accepted Answer

getItemLayout removes the need to calculate item dimensions dynamically, speeding up direct scrolling; windowSize sets the number of offscreen windows to retain; and initialNumToRender sets the initial number of rendered items.

Question 3

What are the differences between TouchableOpacity, TouchableHighlight, and Pressable, and why should we generally use Pressable?

Accepted Answer

Pressable is the newer, more flexible, and more precise component. It provides direct access to multiple interaction states (Pressed, Hovered, Focused) and long-press handling without the complexity of older wrappers.

Question 4

How does the Image component work in React Native, and what common cache limitations and issues does it have?

Accepted Answer

Image loads and displays local and network images, but has limited caching on Android and can repeatedly download images and flicker compared with specialized libraries such as expo-image.

Question 5

How do you use SectionList to show categorized data grouped into sections with sticky headers?

Accepted Answer

SectionList displays structured data divided into sections, each with a title and a group of items, and can automatically keep the header at the top of the screen while scrolling.

Question 6

How do you handle the keyboard covering inputs with KeyboardAvoidingView?

Accepted Answer

Wrap input fields in KeyboardAvoidingView and set the appropriate behavior ("padding" on iOS and "height" or an AndroidManifest adjustment on Android).

Question 7

What is a Modal in React Native, and how should pop-up windows be handled?

Accepted Answer

The Modal component displays content in a window floating above the current app screen. It uses native system modules and supports appearance and fade animations and handling the Android back button.

Question 8

What is SafeAreaView, how has it evolved in React Native, and how does it integrate with react-native-safe-area-context?

Accepted Answer

SafeAreaView keeps content from being covered by screen notches, the Dynamic Island, rounded screen corners, and bottom navigation bars.

Question 9

How do you manage multiple TextInput fields and move focus between them?

Accepted Answer

Use refs to connect TextInput elements and call .focus() on the next field when the keyboard's submit button is pressed (onSubmitEditing), with returnKeyType="next".

Question 10

What is the difference between Switch and ActivityIndicator, and how do you customize their appearance across platforms?

Accepted Answer

Switch displays the operating system's native logical On/Off control, while ActivityIndicator displays a circular loading spinner. Both support color and size customization to match the app's identity.