useDebouncedValue in React
React interview exercise on Custom hooks, difficulty 2 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Write useDebouncedValue(value, ms): returns `value` as it was once it has stopped changing for ms milliseconds. While it keeps changing, the hook keeps returning the last settled value; the very first value is returned at once.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.