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React useEffect not firing on state update with conditional dependency

πŸ‘€ Views: 4 πŸ’¬ Answers: 1 πŸ“… Created: 2025-06-01
reactjs hooks useeffect javascript

I'm trying to figure out I'm stuck on something that should probably be simple. I've searched everywhere and can't find a clear answer. I'm working with an scenario where my `useEffect` hook in React isn't firing as expected when a specific state variable changes. I'm using React version 17.0.2 and I have a component that fetches data based on a search term. Here's a snippet of my code: ```javascript import React, { useState, useEffect } from 'react'; const SearchComponent = () => { const [searchTerm, setSearchTerm] = useState(''); const [results, setResults] = useState([]); useEffect(() => { if (searchTerm) { const fetchResults = async () => { const response = await fetch(`https://api.example.com/search?q=${searchTerm}`); const data = await response.json(); setResults(data.results); }; fetchResults(); } }, [searchTerm]); const handleChange = (e) => { setSearchTerm(e.target.value); }; return ( <div> <input type="text" onChange={handleChange} placeholder="Search..." /> <ul> {results.map((result) => <li key={result.id}>{result.name}</li>)} </ul> </div> ); }; export default SearchComponent; ``` The question is that when I type in the input field, the `useEffect` hook does not seem to trigger the fetch call if I backtrack and delete the search term character by character. For example, if I start typing 'cat', it works fine. However, if I delete the 'c' and only type 'at', the `useEffect` doesn't fire, and I see no new request being made. The console doesn't log any errors. I've already confirmed that `setSearchTerm` is updating correctly by adding a `console.log(searchTerm);` inside the `handleChange` function. I’ve also checked that the API endpoint returns the expected data. I suspect it might have something to do with how React handles closures or state updates within `useEffect`, but I’m not sure how to track down the question. Any insight into why it’s not firing under these conditions would be greatly appreciated! Am I missing something obvious? This is for a application running on Windows 10. Thanks in advance! Thanks for taking the time to read this!