Understanding React Hooks

Introduction to React Hooks

React Hooks revolutionized the way we write React components by allowing us to use state and other React features in functional components. Before hooks, we had to use class components for stateful logic, which often led to complex and hard-to-maintain code.

What are React Hooks?

Hooks are functions that let you "hook into" React state and lifecycle features from function components. They don't work inside classes — they let you use React without classes.

The useState Hook

The most commonly used hook is useState. It allows you to add state to functional components:

The useEffect Hook

The useEffect hook lets you perform side effects in function components. It serves the same purpose as componentDidMount, componentDidUpdate, and componentWillUnmount combined in React classes.

Custom Hooks

One of the most powerful features of hooks is the ability to create your own custom hooks. Custom hooks allow you to extract component logic into reusable functions.

Best Practices

• Only call hooks at the top level of your React functions
• Only call hooks from React function components or custom hooks
• Use the ESLint plugin for hooks to catch common mistakes
• Keep related state together when possible

Conclusion

React Hooks provide a more direct API to the React concepts you already know. They offer a powerful and flexible way to reuse stateful logic between components, making your code more readable and maintainable.

import React, { useState } from 'react';

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

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}

import React, { useState, useEffect } from 'react';

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

  useEffect(() => {
    document.title = `You clicked ${count} times`;
  });

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  );
}