React Native is an open-source framework for building native mobile applications using JavaScript and React. It allows developers to use the same codebase for iOS and Android platforms.
React Native Anti-Patterns Overview
React Native, while powerful for cross-platform mobile development, has several common anti-patterns that can lead to performance issues, maintenance problems, and poor user experience. Here are the most important anti-patterns to avoid when writing React Native code.
Inefficient List Rendering
Using ScrollView
with map
for long lists leads to performance issues as it renders all items at once. Use FlatList
or SectionList
for efficient list rendering with windowing and recycling.
Not Using React Native's PureComponent or memo
Regular components re-render even when props haven’t changed. Use React.memo
for functional components or PureComponent
for class components to prevent unnecessary re-renders.
Layout Thrashing
Multiple state updates that affect layout cause performance issues. Batch layout changes and use the Animated API with useNativeDriver
when possible.
Not Using useCallback for Event Handlers
Creating new function instances on every render can cause unnecessary re-renders in child components. Use useCallback
to memoize functions.
Inline Styles
Inline styles are recreated on every render and can’t be optimized by React Native. Use StyleSheet.create()
to define styles outside the component.
Not Using Proper Image Optimization
Loading full-size images for small UI elements wastes bandwidth and memory. Request appropriately sized images and use proper resizeMode
.
Not Using React Navigation Properly
Not Handling Platform Differences Properly
Scattering platform-specific code makes components hard to maintain. Use Platform.select()
or platform-specific files (e.g., Component.ios.js
and Component.android.js
).
Not Using Proper State Management
Prop drilling makes components tightly coupled and hard to maintain. Use Context API for simpler apps or Redux/MobX for complex state management.
Not Handling Permissions Properly
Not handling permissions properly leads to crashes and poor user experience. Always check and request permissions before using device features.
Not Using Proper Error Boundaries
Without error boundaries, a single component crash can bring down the entire app. Use error boundaries to gracefully handle component errors.
Not Using Proper Accessibility Features
Ignoring accessibility makes your app unusable for many users. Include accessibility props like accessible
, accessibilityLabel
, and accessibilityHint
.
Not Optimizing App Launch Time
Heavy operations during app launch increase startup time. Defer non-critical operations and use splash screens with AppLoading
component.
Not Using Hermes Engine
Not using Hermes (JavaScript engine optimized for React Native) can result in slower startup times and higher memory usage. Enable Hermes for better performance, especially on Android.