简单实现 MVVM

const data = {};
const input = document.getElementById("input");

Object.defineProperty(data, "text", {
  set(value) {
    input.value = value;
    this.value = value;
  },
});

input.onchange = function (e) {
  data.text = e.target.value();
};

var instance = null;

class Storage {
    static getInstance() {
        if (!instance) {
            instance = new Storage();
        }
        return instance;
    }
    setItem = (key, value) => localStorage.setItem(key, value),
    getItem = key = > localStorage.getItem(key)
}