Unexpected Behavior When Using Async Functions in a Loop with React State Updates
I'm reviewing some code and Quick question that's been bugging me - I'm relatively new to this, so bear with me. I'm working on a project and hit a roadblock. I'm encountering an issue when trying to update state inside a loop with asynchronous operations in a React component. I'm using React 17 and have a function that fetches data for multiple items based on an array of IDs, but the state updates don't seem to reflect the latest data after each fetch. Here's the relevant code snippet: ```javascript import React, { useState } from 'react'; const MyComponent = () => { const [data, setData] = useState([]); const fetchData = async (id) => { const response = await fetch(`https://api.example.com/data/${id}`); return response.json(); }; const handleFetch = async () => { const ids = [1, 2, 3]; for (const id of ids) { const result = await fetchData(id); setData(prevData => [...prevData, result]); // State update here } }; return ( <div> <button onClick={handleFetch}>Fetch Data</button> <pre>{JSON.stringify(data, null, 2)}</pre> </div> ); }; export default MyComponent; ``` When I click the button to trigger `handleFetch`, I expect to see the data for all three IDs in the rendered output. However, it seems that the state only reflects the data for the last ID fetched, and the previous ones are missing. I also tried using `setData` with a functional update, but it doesn't resolve the issue. Is there a way to ensure that all fetched data gets properly accumulated in the state? Also, I've noticed that if I replace the loop with `Promise.all()`, it seems to work correctly but I'd prefer to keep the sequential fetching for rate-limiting reasons. Any insights into why this might be happening or how to resolve it would be greatly appreciated! For context: I'm using Javascript on Windows. This is part of a larger CLI tool I'm building. Has anyone else encountered this? The project is a CLI tool built with Javascript. Thanks for any help you can provide! This is happening in both development and production on Debian. Could someone point me to the right documentation?