React Hooks Complete Guide: useState, useEffect, and More

React Hooks, introduced in React 16.8, fundamentally changed how we write React components. They let you use state and other React features in functional components — no classes required. This guide covers every built-in hook with real examples, common patterns, and the pitfalls to avoid. Why Hooks? Before hooks, stateful logic was locked inside class components, which led to several problems: complex lifecycle methods that forced unrelated logic together, difficulty reusing stateful logic between components, and confusing this bindings. Hooks solve all of these by letting you extract stateful logic into reusable functions. useState The most fundamental hook. useState adds state to a functional component and returns the current value plus a function to update it. import { useState } from 'react'; function Counter() { const [count, setCount] = useState(0); // initial value: 0 return ( <div> <p>Count: {count}</p> <button onClick={() => setCount(count + 1)}>+&lt