Why FlatList handles large datasets efficiently in React Native - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import FlatList from React Native.

React Native

import { [1] } from 'react-native';

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AScrollView

BFlatList

CListView

DView

Attempts:

3 left

💡 Hint

Common Mistakes

Using ScrollView instead of FlatList for large lists.

The FlatList component is imported from react-native to efficiently render large lists.

2fill in blank

medium

Complete the code to provide data to FlatList using the correct prop.

React Native

<FlatList data=[1] renderItem={({item}) => <Text>{item}</Text>} />

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Asource

Blist

Cdata

Ditems

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'items' or 'source' instead of 'data'.

The data prop is used to pass the array of items to FlatList.

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hard

Fix the error in the keyExtractor prop to avoid warnings about missing keys.

React Native

<FlatList data={myData} renderItem={({item}) => <Text>{item.name}</Text>} keyExtractor={item => item[1] />

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Avalue

Bkey

Cindex

Did

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'index' or 'key' which may not be unique or stable.

The keyExtractor should return a unique string key, usually the id of the item.

4fill in blank

hard

Fill both blanks to enable FlatList to render only visible items and improve performance.

React Native

<FlatList data={items} renderItem={renderItem} initialNumToRender=[1] maxToRenderPerBatch=[2] />

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A10

B100

C1

D50

Attempts:

3 left

💡 Hint

Common Mistakes

Rendering all items at once causing performance issues.

Setting initialNumToRender to 10 and maxToRenderPerBatch to 50 helps FlatList render only a small batch of items at a time, improving efficiency.

5fill in blank

hard

Fill all three blanks to implement FlatList with windowSize and removeClippedSubviews for better memory use.

React Native

<FlatList data={data} renderItem={renderItem} windowSize=[1] removeClippedSubviews=[2] keyExtractor={item => item.[3] />

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A5

Btrue

Cid

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Not using removeClippedSubviews or wrong keyExtractor causing performance issues.

Setting windowSize to 5 and removeClippedSubviews to true helps FlatList keep only visible items in memory. The keyExtractor uses 'id' for unique keys.