useState is a React Hook used to store and update data in a component.

For example:

Counter value

Username

Login status

Shopping cart items.

Basic syntax:

const [state, setState] = useState(initialValue);

state — current value.

setState — function to update the value.

useState(initialValue) — sets the starting value.

Example: Counter app:

import { useState } from "react";

function App() {

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

return (

Count: {count}

<button onClick={() => setCount(count + 1)}> Increase </button> </div>

);

}

export default App;

How it works:

useState(0) sets the initial count to 0.

count stores the current number.

When you click Increase, setCount(count + 1) updates the number.

React re-renders the component to show the new value.

Example:

Change a name

import { useState } from "react";

function App() {

const [name, setName] = useState("Sathish");

return (

Hello, {name}!

setName("Kumar")}>

Change Name

);

}

export default App;

Before clicking: Hello,…