Web Storage是HTML5中新增的除Canvas元素以外,非常非常重要的功能!没有之一!顾名思义,其就是在Web端存储数据的功能,当然这里的存储只是针对客户端本地而言的。
localStorage与sessionStorage是Web Storage提供的两种存储在客户端的方法。 localStorage:没有时间限制的存储方式。存储的时间可以是一天,二天,几周或几十年!关闭浏览器数据不会随着消失,当再次打开浏览器时,数据依然可以访问!也就是说除非你主动删除数据,否则数据是永远不会过期的。 sessionStorage:保存在session对象当中。用来保存的时间为用户与浏览器的会话时间。即从浏览页面到关闭浏览器为一个会话时间。关闭浏览器,所有的 session数据也会消失!
//保存数据有3种方法:
sessionStorage.setItem("key","value");
//或
sessionStorage.key="value";
//或
sessionStorage["key"]="value";
//读取数据的3种方法,将数据赋值给变量v
var v=sessionStorage.getItem("key");
//或
var v=sessionStorage.key;
//或
var v=sessionStorage["key"];
//保存数据有3种方法:
localStorage.setItem("key","value");
//或
localStorage.key="value";
//或
localStorage["key"]="value";
//读取数据的3种方法,将数据赋值给变量v
var v=localStorage.getItem("key");
//或
var v=localStorage.key;
//或
var v=localStorage["key"];
//保存数据userName值为zhangpeiyue
sessionStorage.set("userName","zhangpeiyue");
//也可以写为:
window.sessionStorage.set("userName","zhangpeiyue");
//添加2条localStorage,1条sessionStorage
localStorage.a=1;
localStorage.b=2;
sessionStorage.a=3;
console.log(localStorage.length);//2
console.log(sessionStorage.length);//1
localStorage.userName="zhangpeiyue";
localStorage.age=18;
console.log(localStorage.key(0));//age
console.log(localStorage[localStorage.key(0)]);//18
console.log(localStorage.key(1));//userName
console.log(localStorage[localStorage.key(1)]);//zhangpeiyue
localStorage.userName="zhangpeiyue";
localStorage.age=18;
//移除key为userName的数据
localStorage.removeItem("userName");
console.log(localStorage.userName);//undefined
console.log(localStorage.age);//18
localStorage.userName="zhangpeiyue";
localStorage.age=18;
console.log(localStorage.userName);//zhangpeiyue
console.log(localStorage.age);//18
localStorage.clear();//清除所有localStorage的数据
console.log(localStorage.userName);//undefined
console.log(localStorage.age);//undefined