Complete Guide to React Hooks

React Hooks revolutionized the way we write React components. In this comprehensive guide, we'll explore the most important hooks and how to use them effectively.

What are Hooks?

Hooks are functions that allow you to "hook into" React features from functional components. Before Hooks, you needed class components to access features like state and lifecycle methods.

Essential Hooks

useState

The most commonly used hook, useState lets you add state to functional components:

const [count, setCount] = useState(0);

const increment = () => setCount(count + 1);

useEffect

Handle side effects like data fetching, subscriptions, and DOM manipulation:

useEffect(() => {
  // This runs after every render
  console.log('Component rendered');
}, []); // Empty dependency array runs only once

useContext

Access context values without prop drilling:

const theme = useContext(ThemeContext);

useReducer

Complex state logic? useReducer is your friend:

const [state, dispatch] = useReducer(reducer, initialState);

Rules of Hooks

Only call Hooks at the top level - Don't call them in loops or conditions
Only call Hooks from React functions - Call them from functional components or custom hooks
Use custom hooks to share stateful logic - Extract hook logic into reusable functions

Best Practices

Keep your components focused and use custom hooks for reusable logic
Use the ESLint plugin eslint-plugin-react-hooks to enforce hook rules
Memoize callbacks and values with useCallback and useMemo when needed

Conclusion

Hooks make React development more intuitive and powerful. Master these fundamental hooks and you'll write cleaner, more efficient React code.