👀 Views: 0 💬 Answers: 1 📅 Created: 2025-06-18

react setstate useState JavaScript

I'm maintaining legacy code that I'm working with an scenario while trying to update a nested state object in a functional React component using the `setState` method... The state structure looks like this: ```javascript const [formData, setFormData] = useState({ user: { name: '', age: 0, }, preferences: { theme: 'light', notifications: true, } }); ``` When I try to update the `name` property of the `user` object using the following code: ```javascript const updateName = (newName) => { setFormData(prevState => { return { ...prevState, user: { ...prevState.user, name: newName } }; }); }; ``` I expect that `formData.user.name` will update correctly. However, what I'm experiencing is that sometimes, the `name` does not update as expected, and I see the following warning in the console: `Warning: want to update a component (MyComponent) while rendering a different component (MyOtherComponent)`. This behavior is inconsistent; it works fine for certain inputs but fails for others. I've tried using `React.useCallback` for `updateName`, but the scenario continues. I also ensured that the function is not called during the rendering process directly, and I'm invoking `updateName` only in response to a button click. Here's the button code that triggers the update: ```javascript <button onClick={() => updateName('John Doe')}>Update Name</button> ``` I'm using React 18 and functional components. Is there something I'm missing regarding state updates or side effects that could lead to this kind of warning? Any insights would be greatly appreciated! Any ideas how to fix this? I'm working on a CLI tool that needs to handle this. Any examples would be super helpful.