RCT.12.05 Mid-levelCore — asked often

useInterval, useTimeout, useEventListener, useClickOutside

Comes up in: React, Coding

This concept is being written. It gets the full five steps — explanation, predict, interview angle, practice with tests, and review cards. Here is exactly what it will cover, so you can study it elsewhere in the meantime.

What it covers

latest callback ref pattern (or useEffectEvent)
pausing with null delay
listener cleanup
outside click with portals

Words you will know

—

What you will practise

implement 4 hooks

Interview questions this answers

Implement useInterval that always calls the latest callback.
Implement useClickOutside.