FrontendHaltReact·Intermediate·Coding·1 min read
What makes a custom Hook different from an ordinary function?
Short interview answer
A custom Hook calls other Hooks and packages reusable stateful behavior. It shares logic, not one state instance: each component call receives independent hook state unless the hook deliberately connects them to a shared external store.
Example
function useToggle(initial = false) { const [on, setOn] = useState(initial); const toggle = useCallback(() => setOn((v) => !v), []); return [on, toggle];}// Two components calling useToggle() get two independent states.Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.