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How to Import useState in React?

Published in React Hooks 2 mins read

To import the useState hook in React, you must use the following import statement: import { useState } from 'react';

Understanding the useState Hook

The useState hook is a fundamental part of React that allows functional components to manage state. State refers to data that can change over time and trigger UI updates in your application. To use useState, you first need to import it from the React library.

How to Use useState

Once imported, you use it within a functional component like this:

import { useState } from 'react';

function MyComponent() {
  const [age, setAge] = useState(42);
  const [name, setName] = useState('Taylor');
    // ... other code
}

Here is a breakdown of what the code does:

  • import { useState } from 'react';: This line specifically imports the useState hook, making it available for use in the component.
  • const [age, setAge] = useState(42);: This line does several things:
    • It declares a state variable named age, initialized to the value 42.
    • It declares a function called setAge, which is used to update the value of age.
    • The initial value of age (42) is set during the first render.
  • const [name, setName] = useState('Taylor');: Similar to the previous line, this creates another state variable called name with an initial value of 'Taylor' and a function setName to update it.

Detailed Explanation

Feature Description
import keyword Used to bring in modules and functionalities from external libraries.
useState A React Hook used to manage state in functional components.
'react' The name of the React library that contains the useState hook.
[state, setState] Array destructuring where the first element holds the current state value and the second holds a function to update that value.
Initial Value The value given to useState on initial render.

Practical Insights

  • You can have multiple useState calls in one component.
  • Each useState declaration manages its own independent piece of state.
  • When the setState function is called, React re-renders the component.

By importing and using useState as shown, you can create dynamic and interactive user interfaces in your React applications.

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