function oldFetch(url, callback) {
  const xhr = new XMLHttpRequest();
  xhr.open('GET', url);
  xhr.onload = () => {
    if (xhr.status === 200) {
      callback(JSON.parse(xhr.response));
    } else {
      callback(null, xhr.status);
    }
  };
  xhr.send();
}

---

## 🔹 Best Practices
1. Always handle errors in promises/async functions
2. Use async/await for better readability
3. Cancel requests when no longer needed (AbortController)
4. Throttle rapid API calls (debounce input handlers)
5. Cache responses when appropriate

---

### 📌 What's Next?
In Part 6, we'll cover:
➡️ JavaScript Modules
➡️ ES6+ Features
➡️ Tooling (Babel, Webpack, npm)

#JavaScript #AsyncProgramming #WebDevelopment 🚀

Practice Exercise:
1. Fetch GitHub user data (https://api.github.com/users/username)
2. Create a function that fetches multiple Pokémon in parallel
3. Build a retry mechanism for failed requests (max 3 attempts)