State Management · Middle · Question 53 of 75

Should you store `cartTotal` in the Redux state next to `items`?

✓Correct answer: No - derive it with a (memoized) selector from items
2Yes - and update it in every reducer that changes items
3Yes - derived values must live in the store

Explanation

Duplicated derived data drifts out of sync. Keep the minimal state and compute the rest in selectors, as the Redux style guide recommends.

Further reading

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