The effect hook called useEffect is used to fetch the data with axios from the API and to set the data in the local state of the component with the state hook’s update function.

Let’s take an example in which it fetches list of react articles from the API

import React, { useState, useEffect } from 'react';
import axios from 'axios';

function App() {
  const [data, setData] = useState({ hits: [] });

  useEffect(() => {
    (async () => {
      const result = await axios(
        'http://hn.algolia.com/api/v1/search?query=react',
      );

      setData(result.data);
    })()
  }, []);

  return (
    <ul>
      {data.hits.map(item => (
        <li key={item.objectID}>
          <a href={item.url}>{item.title}</a>
        </li>
      ))}
    </ul>
  );
}

export default App;

Remember we provided an empty array as second argument to the effect hook to avoid activating it on component updates but only on mounting of the component. i.e, It fetches only on component mount.

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