localStorage封装

 /*设置与获取Cookie*/
 2 var Cookie ={}
 3 Cookie.write = function(key, value, duration){
 4 var d = new Date();
 5 d.setTime(d.getTime()+1000*60*60*24*30);
 6 document.cookie = key + "=" + encodeURI(value) + "; expires=" + d.toGMTString();
 7 };
 8 Cookie.read = function(key){
 9 var arr = document.cookie.match(new RegExp("(^| )"+key+"=([^;]*)(;|$)"));
10 if(arr != null)
11 return decodeURIComponent(arr[2]);
12 return "";
13 };
14 //定义本地存储对象
15 var storage = {
16  getItem:function(key){//假如浏览器支持本地存储则从localStorage里getItem，否则乖乖用Cookie
17  return window.localStorage? localStorage.getItem(key): Cookie.read(key); 
18  },
19  setItem:function(key,val){//假如浏览器支持本地存储则调用localStorage，否则乖乖用Cookie
20   if (window.localStorage) {
21       localStorage.setItem(key,val); 
22   } else {
23    Cookie.write(key,val); 
24   }
25  }
26  };

实例化：

storage.setItem("UserName","张三");//将UserName存进去
if(storage.getItem("UserName"))//假如存进去了
{
 console.log(storage.getItem("UserName"));//打印出来样子
}

因为localStorage存储进去的都是string类型，所以如果要存json记得存前读后做些处理

var myJson={"UserName","张三"};
storage.setItem("MyJson",JSON.stringify(myJson));//将myJson存进去，记得JSON.stringify转成字符串

var getmyJson=JSON.parse(storage.getItem("MyJson"));//取出来的是字符串，记得JSON.parse还原一下