How do you integrate a React application with a back-end API?

There are several ways to integrate a React application with a back-end API, but one common approach is to use the fetch() or axios library to make API calls from the React application to the back-end API.

In a React component, you can make an API call using the fetch() function or axios library inside a lifecycle method, such as componentDidMount(), and use the returned data to update the component's state. This will cause the component to re-render with the new data, which will be displayed on the page.

You can also use a library such as redux-thunk or redux-saga to handle the API calls in a centralized manner and manage the state updates in the Redux store.

Another way is by using the useEffect hook, to make the api call on the component and update the state with the response.

It's worth noting that, the above are just a few of the many ways to integrate a React application with a back-end API, it's best to use the one that fits your project needs.