What are React Hooks and how do I use them?

Can you explain what React Hooks are?

React Hooks are functions that let you use state and other React features without writing a class.

How do I use the useEffect hook to fetch data from an API?

You can use useEffect to perform side effects like data fetching. Here's a basic example:

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

const MyComponent = () => {
  const [data, setData] = useState(null);

  useEffect(() => {
    fetch('https://api.example.com/data')
      .then(response => response.json())
      .then(data => setData(data));
  }, []);

  return <div>{data ? JSON.stringify(data) : 'Loading...'}</div>;
};

What does the empty array in useEffect mean?

The empty array means that the effect runs only once after the initial render, similar to componentDidMount.