REACT

useLocalStorage Hook

A minimal custom React Hook for persisting state to localStorage with TypeScript support (without expiry)

ReactHooksLocalStorageStatePersistence

Code

import { useState, useEffect } from 'react';

function useLocalStorage<T>(key: string, initialValue: T): [T, (value: T | ((val: T) => T)) => void] {
  const [storedValue, setStoredValue] = useState<T>(() => {
    __TOKEN_12__ (typeof window === 'undefined') return initialValue;
    try {
      const item = window.localStorage.getItem(key);
      return item ? JSON.parse(item) : initialValue;
    } __TOKEN_18__ (error) {
      console.warn(`Error reading localStorage key "${key}":`, error);
      return initialValue;
    }
  });

  const setValue = (value: T | ((val: T) => T)) => {
    try {
      const valueToStore = value instanceof Function ? value(storedValue) : value;
      setStoredValue(valueToStore);
      __TOKEN_24__ (typeof window !== 'undefined') {
        window.localStorage.setItem(key, JSON.stringify(valueToStore));
      }
    } __TOKEN_26__ (error) {
      console.warn(`Error setting localStorage key "${key}":`, error);
    }
  };

  return [storedValue, setValue];
}

// Usage example
// const [theme, setTheme] = useLocalStorage('app-theme', 'light');
// const [userSettings, setUserSettings] = useLocalStorage('user-settings', { notifications: true });