Why do we use useState hook in React?

The useState hook in React is a way for a component to manage and update its own state. In React, state refers to a component's internal data and information, such as the values of its variables and the current status of its settings. The useState hook allows a component to maintain its own state and update it as needed without relying on external state management systems or props being passed down from parent components.

Using the useState hook is simple. To use it, a component needs to call the useState function and pass it the initial value of the state it wants to manage. The useState function will then return an array with two elements: the current value of the state and a function that can be used to update the state. The component can then use these two values to access and update its state as needed.

For example, if a component has a state variable called count that stores a number, it could use the useState hook like this:

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

This code would call the useState function and pass it the initial value of 0 for the count state variable. The useState function would then return an array with two elements: the current value of count, which would be 0, and a function called setCount that can be used to update the value of count.

The component could then use the count variable to access the current value of its state, and it could use the setCount function to update the value of count as needed. For example, if the component wanted to increment the value of count by one, it could do so like this:

setCount(count + 1); 

This code would call the setCount function and pass it the new value of count, which would be the current value of count plus one. The setCount function would then update the value of count to the new value, and the component could use the updated value of count in its render function or other logic as needed.

Overall, the useState hook provides a simple and convenient way for a component to manage and update its own state, which makes the component's code easier to read and understand and makes the component more flexible and reusable.