nakamurakko https://blog.hatena.ne.jp/nakamurakko/ nakamurakko’s blog https://nakamurakko.com/ React 環境 React 19.1 dependencies が同じ useEffect を定義した場合、 dependencies が変更されたタイミングで、どちらも呼び出される。 import './App.css'; import React, { useEffect, useState } from 'react'; export default function App(): React.JSX.Element { const [clickCount, setClickCount] = useState<number>(0); const [text, setText] = useState… 190 <iframe src="https://hatenablog-parts.com/embed?url=https%3A%2F%2Fnakamurakko.com%2Fentry%2F2025%2F08%2F25%2F180253" title="React useEffect の dependencies に気を付ける - nakamurakko’s blog" class="embed-card embed-blogcard" scrolling="no" frameborder="0" style="display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;"></iframe> https://cdn-ak.f.st-hatena.com/images/fotolife/n/nakamurakko/20250825/20250825162258.png Hatena Blog https://hatena.blog 2025-08-25 18:02:53 rich https://nakamurakko.com/entry/2025/08/25/180253 1.0 100%