React HooksLesson 53Free preview

React useMemo

This lesson is part of React · All levels

Summary

UseMemo returns the value of the already-memoized computation result so that it is only recalculated when the dependencies change. It's great for expensive processes like filtering thousands of data or formatting complex data formats. Use it after there's actually a performance problem, not as a habit from the start.

Key points

The shape
Preventing repeated weight calculations on each render
Returns a value, unlike useCallback which returns a function
An incomplete dependence can create a worthless value

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