单例模式

[J-DuYa]

• [ ] 概念讲解

• [ ] 原理解析

• [ ] 代码实现

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

}