How do I use useEffect in React?

How do I use useEffect in React?

The useEffect hook lets you perform side effects in function components. What specific use case do you have in mind?

I want to fetch data from an API when the component mounts.

You can do that by passing a function to useEffect that fetches the data, and an empty dependency array to run it once on mount.

Can you show me a code example?

Sure! Here's a simple 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>;
};

This fetches data when the component mounts.