React useLocalStorage hook: Creates a stateful value that is persisted to localStorage, and a function to update it.

useLocalStorage.jsx

const useLocalStorage = (keyName, defaultValue) => {
  const [storedValue, setStoredValue] = React.useState(() => {
    try {
      const value = window.localStorage.getItem(keyName);

      if (value) {
        return JSON.parse(value);
      } else {
        window.localStorage.setItem(keyName, JSON.stringify(defaultValue));
        return defaultValue;
      }
    } catch (err) {
      return defaultValue;
    }
  });

  const setValue = newValue => {
    try {
      window.localStorage.setItem(keyName, JSON.stringify(newValue));
    } catch (err) {}
    setStoredValue(newValue);
  };

  return [storedValue, setValue];
};


const MyApp = () => {
  const [name, setName] = useLocalStorage('name', 'John');

  return <input value={name} onChange={e => setName(e.target.value)} />;
};


ReactDOM.createRoot(document.getElementById('root')).render(
  <MyApp />
);