👀 Views: 3 💬 Answers: 1 📅 Created: 2025-06-06

react setinterval useeffect JavaScript

Hey everyone, I'm running into an issue that's driving me crazy. I'm working with a question with a component that uses `setInterval` to fetch data periodically. When the component unmounts, I use `clearInterval` to stop the interval, but it seems like the interval is still running even after the component is removed from the DOM. This leads to unexpected behavior, including multiple fetch requests being triggered when the component is remounted. I am using React 17 and the component is structured as follows: ```javascript import React, { useEffect, useState } from 'react'; const DataFetcher = () => { const [data, setData] = useState(null); useEffect(() => { const intervalId = setInterval(() => { fetch('https://api.example.com/data') .then((response) => response.json()) .then((result) => setData(result)); }, 5000); return () => clearInterval(intervalId); }, []); return <div>{data ? JSON.stringify(data) : 'Loading...'}</div>; }; export default DataFetcher; ``` I've made sure that `clearInterval` is indeed called by adding a console log just before it: ```javascript return () => { console.log('Clearing interval'); clearInterval(intervalId); }; ``` However, the log appears to show up correctly, yet I still see network requests being made after unmounting. I’ve double-checked that there are no other components that might be starting a new interval. Is there something I'm missing, or is there a better way to handle this in React? Any help would be appreciated! I'm working on a service that needs to handle this. Has anyone else encountered this?