window.fakeStorage = { _data: {}, setItem: function (id, val) { return this._data[id] = String(val); }, getItem: function (id) { return this._data.hasOwnProperty(id) ? this._data[id] : undefined; }, removeItem: function (id) { return delete this._data[id]; }, clear: function () { return this._data = {}; } }; function LocalScoreManager() { this.key = "bestScore"; var supported = this.localStorageSupported(); this.storage = supported ? window.localStorage : window.fakeStorage; } LocalScoreManager.prototype.localStorageSupported = function () { var testKey = "test"; var storage = window.localStorage; try { storage.setItem(testKey, "1"); storage.removeItem(testKey); return true; } catch (error) { return false; } }; LocalScoreManager.prototype.get = function () { return this.storage.getItem(this.key) || 0; }; LocalScoreManager.prototype.set = function (score) { this.storage.setItem(this.key, score); };