useState

useState is a hook in React that adds state to functional components. It is a way to use state in functional components, which were not able to have state before the introduction of hooks.

Here is an example of using the useState hook to add state to a functional component:

import { useState } from 'react'

function Example() {
  // Declare a new state variable, which we'll call "count"
  const [count, setCount] = useState(0)

  return (
    <div>
      <p>You clicked {count} times</p>
      <button onClick={() => setCount(count + 1)}>
        Click me
      </button>
    </div>
  )
}

In this example, the useState hook is called with an initial state of 0. This returns an array with two elements: the current state value and a function to update the state. The state value is destructured into a count variable, and the update function is destructured into a setCount function.

The count variable is used to display the current count, and the setCount function is called with a new value when the button is clicked to update the value of count.

The useState hook can be called multiple times in a single component to manage multiple pieces of state. It is a very useful and powerful way to add state to functional components in React.

You can use the useState hook whenever you want to add state to a functional component. It is a way to use state in functional components, which were not able to have state before the introduction of hooks.

Here are a few examples of when you might want to use the useState hook:

  • When you want to store a value that will change over time, such as a user’s input or a timer.
  • When you want to store a value that will be updated based on user interaction, such as a form submission or a button click.
  • When you want to store a value that will be used by multiple components, and you want to avoid the “prop drilling” problem that can arise when passing props down through a deeply nested component hierarchy.

Overall, the useState hook is a very useful and powerful way to add state to functional components in React. It can be used in a wide variety of situations to store values that change over time and enable your components to be more interactive and dynamic.

When to use React useState ?

The useState() hook in React is used to add state to a functional component. It allows you to keep track of a value that changes over time, and update the component’s UI in response to those changes.

Here are some common use cases where useState() can be useful:

  1. Form inputs: When you have a form input and you need to keep track of the input value and update the component’s UI in response to changes, you can use useState() to store the input value and update it as the user types.
  2. Toggles and switches: When you need to toggle a value between true and false, such as a switch to turn something on or off, you can use useState() to store the value and update it when the switch is clicked.
  3. Dynamic lists: When you need to create a list of items, such as a list of to-do items, you can use useState() to store the list of items and update it when an item is added or removed.
  4. Keeping track of user interactions: When you need to keep track of how a user interacts with your component, such as how many times a button has been clicked, you can use useState() to store the count and update it whenever the button is clicked.
  5. Fetching data: When you need to fetch data from an API and update the component’s UI in response to the data, you can use useState() to store the data and update it when the data is successfully fetched.

It’s important to note that useState() should be used for simple state management within a component, for more complex state management usecases, consider to use state management libraries such as Redux or Mobx.

useState