Level Up React: Deep Dive into State and useState

React's useState hook might seem simple at first glance, but there's much more to it than meets the eye. In this article, we'll explore everything you need to know about managing state in React functional components.

What you'll learn

• How useState actually works behind the scenes
• Why state updates are asynchronous and how to handle this correctly
• Techniques for optimizing performance with lazy initialization
• Best practices for working with complex state objects
• Common pitfalls and how to avoid them
• When to use useState vs useReducer

A taste of what's covered

The asynchronous nature of state updates often catches developers by surprise:

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

  const handleClick = () => {
    setCount(count + 1);
    console.log(count); // Still shows the old value!
  };

  return (
    <button onClick={handleClick}>
      Increment ({count})
    </button>
  );
}

We explore solutions like using the functional update pattern:

setCount(prevCount => prevCount + 1);

We also cover advanced topics like performance optimization in React 19:

// The expensive processing only runs when data changes
const processedData = useMemo(() => {
  return data.map(item => /* complex processing */);
}, [data]);

This article aims to be a comprehensive resource for both beginners and experienced React developers who want to improve their understanding of state management.

Read the full article at: Level Up React: Deep Dive into State and useState