When should I use useCallback over useMemo?
When you pass a function as a prop to a child wrapped in React.memo, or when a handler is used in a child's effect. The stable function reference prevents unnecessary re-renders and effect re-runs.
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More FAQs in useMemo vs useCallback: What's the Real Difference?
useMemo memoizes a value by running a function and caching the result. useCallback memoizes a function reference without running it. Use useMemo for expensive computations and useCallback for stable function references passed to memoized children.
No, though they are related. useCallback is essentially useMemo for a function reference. Use useCallback when you need a stable function, and useMemo when you need to cache a computed value. They have distinct purposes.
When you have an expensive computation, like sorting a list or deriving a value, that would otherwise run on every render. Also when you want to keep an object or array reference stable for memoized children.
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