error handling in React vs. error handling in Node.js works differently because one is client-side (React) and the other is server-side (Node.js).

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Error Handling in React (Frontend)

React focuses on UI rendering, so errors usually happen in:

• Components
• Event handlers
• Network requests (API calls)

Methods:

Error Boundaries (for rendering errors)
Catch errors in React component tree during rendering, lifecycle methods, and constructors.

class ErrorBoundary extends React.Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }

  static getDerivedStateFromError(error) {
    return { hasError: true };
  }

  componentDidCatch(error, info) {
    console.error(error, info);
  }

  render() {
    if (this.state.hasError) {
      return <h1>Something went wrong.</h1>;
    }
    return this.props.children; 
  }
}

Try…Catch in Event Handlers

const handleClick = () => {
  try {
    // some logic
  } catch (error) {
    console.error(error);
  }
};

Promise/Catch or Async/Await for API Calls

async function fetchData() {
  try {
    const res = await fetch('/api/data');
    const data = await res.json();
  } catch (error) {
    console.error('API call failed', error);
  }
}

Note:

• Error Boundaries do not catch errors in event handlers or async code.
• Use libraries like react-error-boundary for better patterns.

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Error Handling in Node.js (Backend)

Node handles server logic, file I/O, database, and APIs, so it needs robust error handling.

Methods:

Try…Catch in Async/Await Functions

app.get('/data', async (req, res) => {
  try {
    const data = await getDataFromDB();
    res.json(data);
  } catch (error) {
    console.error(error);
    res.status(500).send('Server error');
  }
});

Express Error Middleware

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).send('Something broke!');
});

Global Uncaught Exception Handling

process.on('uncaughtException', (err) => {
  console.error('Uncaught Exception:', err);
  process.exit(1); // exit to avoid corrupted state
});

process.on('unhandledRejection', (reason, promise) => {
  console.error('Unhandled Rejection:', reason);
});

Note:

• Always handle errors in asynchronous code (e.g., DB queries, file reads, API calls).
• In production, avoid leaking sensitive error details to the client.

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Quick Comparison

Feature	React (Frontend)	Node.js (Backend)
Scope	UI rendering & user interaction	Server logic, DB, APIs
Main Tools	Error Boundaries, try/catch	Try/catch, middleware
Catches Render Errors	✅	❌ (not applicable)
Handles Async Errors	Needs manual try/catch	Built for async error handling
Global Handling	Limited	process.on('error') events

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