Expo React Native JavaScript Best Practices
Guidelines for building high-quality Expo React Native applications with JavaScript, focusing on clean code, modularity, and performance.
Code Style and Structure
- Clean, Readable Code: Ensure your code is easy to read and understand. Use descriptive names for variables and functions.
- Functional Components: Prefer functional components with hooks (useState, useEffect) over class components
- Component Modularity: Break components into smaller, reusable pieces with single responsibility
- Feature-Based Organization: Group related components, hooks, and styles into feature directories (e.g., user-profile, chat-screen)
Naming Conventions
- Variables and Functions: Use camelCase (e.g.,
isFetchingData,handleUserInput) - Components: Use PascalCase (e.g.,
UserProfile,ChatScreen) - Directories: Use lowercase hyphenated names (e.g.,
user-profile,chat-screen)
JavaScript Usage
- Minimize global variables to prevent unintended side effects
- Leverage ES6+ features like arrow functions, destructuring, and template literals to write concise code
- Use PropTypes for type checking if not using TypeScript
Performance Optimization
- Avoid unnecessary state updates; use local state when needed
- Apply
React.memo()to prevent unnecessary re-renders - Optimize FlatList with the following props:
removeClippedSubviewsmaxToRenderPerBatchwindowSize
- Avoid anonymous functions in
renderItemor event handlers
UI and Styling
- Use
StyleSheet.create()for consistent styling or Styled Components for dynamic styles - Ensure responsive design across screen sizes and orientations
- Use optimized image libraries like
react-native-fast-image
Best Practices
- Follow React Native's threading model for smooth UI performance
- Use Expo's EAS Build and OTA updates for deployment
- Expo Router: Use Expo Router for file-based routing in your React Native app. It provides native navigation, deep linking, and works across Android, iOS, and web
