useEffect - common use cases and alternatives ¹ ²

Use Case	Alternative
Updating state based on props or state Caching expensive calculations Transforming data	Compute on each render, consider a memo if expensive.
Resetting all state when a prop changes	Use key prop to reset state.
Adjusting some state when a prop changes	Compute on each render, consider a memo if expensive. If unavoidable (e.g. new state depends on previous state or props) call setState directly during render.
Sharing logic between event handlers	Put the shared logic into a function that you call from both event handlers.
Sending a POST request Responding to an event handler Responding to user events	Use event handlers, or state transitions.
Chains of computations	Calculate what you can during rendering, and adjust the state in the event handler.
Notifying parent components about state changes Passing data to the parent Communicating with parents	Move calls to parent props in to event handlers.
Subscribing to an external store Interacting with browser APIs	useSyncExternalStore.
Fetching data	react-query, react-router, apollo-client, useLoaderData, getServerSideProps, RSC, SWR, use, react-async, use-async-query, react-hooks-fetch.
Initializing the application Initializing global singletons	Call them outside of the component.
Synchronization Effects ("Effects that are caused by rendering itself rather than by a particular event")	✅

Footnotes