storage.js

class Storage {
    static get(key) {
        try {
            return JSON.parse(localStorage.getItem(key));
        } catch (e) {
            return null;
        }
    }

    static set(key, value) {
        localStorage.setItem(key, JSON.stringify(value));
    }

    static exists(key) {
        return !!Storage.get(key);
    }
}