React · Middle · Question 67 of 75

Why is it fine to call `setState` inside `useEffect` that depends on `userId` to fetch data?

✓Correct answer: Fetching synchronizes the component with an external system (the server); just add cleanup to ignore stale responses
2It isn't - effects must never set state
3Because userId is a prop

Explanation

Data fetching is a legitimate effect, though frameworks and libraries (TanStack Query, RSC) handle caching and races better than manual effects.

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