Custom Hooks

Summary

Your own reusable functions (prefixed `use...`) that extract and share stateful logic between components — the primary code-reuse pattern in modern React.

• 1Extract a repeated `useState`+`useEffect` pattern into a custom hook.
• 2Build `useLocalStorage` or `useDebounce` as a practice custom hook.
• 3Learn that custom hooks are just functions — they don't share state between usages.