How does state management work in React.js?

03 Tem 21:04

To understand state management in React.js, you first need to start with a component's local state. The `useState` hook is all about local state — it's used when you want to manage data that a component holds internally. For example, if you want to count how many times a button is clicked, you can easily create a counter state with `useState(0)`. Meanwhile, `useState` updates the state itself, whereas `useEffect` handles side effects related to state, props, external data, or component lifecycle events (mount, update, unmount). The key difference is that `useState` directly updates the state, while `useEffect` triggers when that state or another factor changes. For sharing state between components, common approaches include prop drilling (passing state down from a parent component as props), Context API (sharing state across the entire app), and Redux (centralized state management). Context API is great for smaller projects because it's simple to set up with just `createContext` and `useContext` — especially useful for global states like theme changes or user sessions. Redux, on the other hand, is ideal for more complex applications; its structured approach with actions, reducers, and a store makes large-scale projects easier to maintain. From my experience, I can set up and run Context API faster than Redux in medium-sized projects, but when the state gets complicated, Redux really shines.