When building interactive web applications with React, one of the most important concepts you’ll encounter is state. State allows your components to “remember” information and update dynamically when something changes — for example, when a user clicks a button.
🔹 What is State?
In React, state is an object that stores data about a component. When the state changes, React automatically re-renders the component to reflect the updated data on the screen.
Think of state as a component’s “memory.”
🔹 Using the useState Hook
The most common way to manage state in functional components is with the useState hook.
Here’s a simple example:
`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>
);
}
export default Counter;
`
** Explanation: **
useState(0) → initializes the state variable count with a value of 0.
count → holds the current state.
setCount → function to update the state.
When you click the button, setCount increases count by 1, and React re-renders the component.
🔹 State vs. Props
Props: Data passed into a component from its parent.
State: Data managed inside the component itself.
In short:
Props = external input
State = internal memory
🔹 Key Rules of State
Never modify state directly. Always use the updater function (setCount).
State updates are asynchronous. Don’t rely on state updating immediately after calling setCount.
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