React 18: Performance issues with dynamic component rendering inside useMemo
I just started working with I'm building a feature where I'm a bit lost with I've searched everywhere and can't find a clear answer..... I'm experiencing significant performance issues when rendering a large list of components conditionally using `useMemo`. The components are being generated based on an array that can change frequently due to user input. When the array updates, the entire component list seems to re-render, causing noticeable lag in UI responsiveness. I tried using `useMemo` to optimize this, but it doesn't seem to be making a difference. Here's a simplified version of what I'm doing: ```jsx import React, { useState, useMemo } from 'react'; const DynamicList = () => { const [items, setItems] = useState(['Item 1', 'Item 2', 'Item 3']); const [inputValue, setInputValue] = useState(''); const handleAddItem = () => { setItems((prev) => [...prev, `Item ${prev.length + 1}`]); }; const renderedItems = useMemo(() => { return items.map((item, index) => <li key={index}>{item}</li>); }, [items]); return ( <div> <input type="text" value={inputValue} onChange={(e) => setInputValue(e.target.value)} /> <button onClick={handleAddItem}>Add Item</button> <ul>{renderedItems}</ul> </div> ); }; export default DynamicList; ``` When I log the performance, I notice that each time I add an item, it triggers heavy re-renders. I tried profiling with the React DevTools, and it shows that each list item component is re-mounting rather than just updating. I also ensured that `key` is unique and appropriate, but nothing seems to help. Is there a better way to handle dynamic lists in React 18 without incurring these performance costs? Alternatively, are there any pitfalls I might be missing with `useMemo`? My development environment is macOS. I'd really appreciate any guidance on this. I'm developing on Windows 10 with Javascript. Is this even possible? I'm working in a CentOS environment. I'd be grateful for any help. I'm developing on Windows 10 with Javascript.