React Hooks — Precise Definition
Hooks are functions that let you “hook into” React state and lifecycle features from function components. Hooks don’t work inside classes…
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Hooks are functions that let you “hook into” React state and lifecycle features from function components. Hooks don’t work inside classes — they let you use React without classes.
(An extract from official React documentation for hooks. https://reactjs.org/docs/hooks-overview.html)