JAVASCRIPT

Persist State with a `useLocalStorage` React Hook

Create a custom `useLocalStorage` hook to effortlessly synchronize React component state with the browser's local storage for data persistence.

import { useState, useEffect } from 'react';

function useLocalStorage(key, initialValue) {
  const [storedValue, setStoredValue] = useState(() => {
    try {
      const item = window.localStorage.getItem(key);
      return item ? JSON.parse(item) : initialValue;
    } catch (error) {
      console.error(error);
      return initialValue;
    }
  });

  useEffect(() => {
    try {
      window.localStorage.setItem(key, JSON.stringify(storedValue));
    } catch (error) {
      console.error(error);
    }
  }, [key, storedValue]);

  return [storedValue, setStoredValue];
}

// Example Usage:
// function ThemeSwitcher() {
//   const [theme, setTheme] = useLocalStorage('app-theme', 'light');

//   const toggleTheme = () => {
//     setTheme(theme === 'light' ? 'dark' : 'light');
//   };

//   return (
//     <button onClick={toggleTheme}>
//       Switch to {theme === 'light' ? 'Dark' : 'Light'} Theme
//     </button>
//   );
// }

How it works: The `useLocalStorage` hook provides a convenient way to store and retrieve state from the browser's `localStorage`. It initializes the state by attempting to read from `localStorage` or uses a provided `initialValue`. An `useEffect` hook then ensures that whenever the state changes, the new value is automatically saved to `localStorage`, allowing data to persist across browser sessions.

Persist State with a `useLocalStorage` React Hook

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