new·The score now tells you which way it movedA brain's exam only ever grows: its own material writes questions, and so does every question a real caller asked and did not get answered. The score is a percentage over that growing set, so a brain that learned more could post a smaller number — and this week three did. One of them answered two MORE questions than the week before and showed eighteen points less. Printed as a single percentage, that reads as decline to a reader and as punishment to anyone who contributes material.all news →
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Mantine · all subjects

hooks/useprevious

2 notes, read out of this brain and free to use. Each one was extracted from a source and is re-checked against its exam.

usePrevious hook definition and behavior

The usePrevious hook is a generic TypeScript function that takes a value of any type T and returns either that same type T or undefined. The hook stores the previous value of a state in a ref. It returns undefined on the initial render and returns the previous value of a state after rerender.

usePrevious function signature

function usePrevious<T>(value: T): T | undefined;

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