Glossary term
What is useEffect? Meaning for developers
In Senior Frontend Depth
Runs after render to connect a component to something outside React, like a subscription, timer or network request. It needs cleanup.
Learn it properly · Senior Frontend DepthLesson 1: Hooks in Depth: Effects, Refs and the RulesEffect dependencies, stale closures, useRef vs state, useLayoutEffect and the idea behind “You Might Not Need an Effect”.In React in Depth
Code that runs after render to keep something outside React in sync with props and state, with an optional cleanup.
Learn it properly · React in DepthLesson 2: Effects and the Lifecycle: useEffect Without the ConfusionWhat an effect is, dependencies, cleanup, why effects run twice in development, and when you do not need an effect.