React Best Practices in 2024

React continues to evolve, and with it, best practices for building applications. Here are the patterns and practices you should follow in 2024.

Component Design

Use Function Components

Function components with hooks are now the standard:

function UserProfile({ userId }) {
  const [user, setUser] = useState(null)
  
  useEffect(() => {
    fetchUser(userId).then(setUser)
  }, [userId])
  
  return user ? <div>{user.name}</div> : <Loading />
}

Keep Components Small and Focused

Each component should have a single responsibility:

// Good: Focused components
function UserAvatar({ src, alt }) {
  return <img className="avatar" src={src} alt={alt} />
}

function UserName({ name }) {
  return <h2 className="user-name">{name}</h2>
}

State Management

Use the Right Tool for the Job

• useState - For local component state
• useReducer - For complex state logic
• Context API - For passing data through component tree
• External libraries - For complex global state (Redux, Zustand, Jotai)

Example: Custom Hook for Data Fetching

function useUser(userId) {
  const [user, setUser] = useState(null)
  const [loading, setLoading] = useState(true)
  const [error, setError] = useState(null)
  
  useEffect(() => {
    setLoading(true)
    fetchUser(userId)
      .then(setUser)
      .catch(setError)
      .finally(() => setLoading(false))
  }, [userId])
  
  return { user, loading, error }
}

Performance Optimization

Use React.memo Wisely

const ExpensiveComponent = React.memo(({ data }) => {
  return <ComplexVisualization data={data} />
}, (prevProps, nextProps) => {
  return prevProps.data.id === nextProps.data.id
})

Lazy Loading

const HeavyComponent = lazy(() => import('./HeavyComponent'))

function App() {
  return (
    <Suspense fallback={<Loading />}>
      <HeavyComponent />
    </Suspense>
  )
}

Testing

Always write tests for your components:

describe('UserProfile', () => {
  it('displays user name', () => {
    render(<UserProfile user={{ name: 'John' }} />)
    expect(screen.getByText('John')).toBeInTheDocument()
  })
})

Conclusion

React best practices evolve with the ecosystem. Stay updated, but remember: the best code is code that your team can understand and maintain. Choose patterns that fit your specific needs!