浅谈localStorage本地存储

localStorage:优点是：容量大，易懂，原生支持。缺点：兼容性差些（IE8以下不支持）,安全性也差些（所以不要保存敏感的信息）。
localStorage的API
localStorage存储的格式为（key，value）的键值对；
localStorage.setItem(key,value);将value存储到key字段;
localStorage.getItem(key);获取以key为键的值;
localStorage.removeItem(key);清除以key为键的value值;
localStorage.clear();清除所有
首先，判断当前浏览器是否支持localStorage
<script type=”text/javascript”>
if(window.localStorage){
alert(“恭喜，您的浏览器支持localStorage”);
}else{
alert(“sorry,请的浏览器不支持”);
}
</script>
如果弹出“恭喜，您的浏览器支持localStorage”那么，就可以开始下面我们的本地存储：
localStorage的三种设置及取出的方法
<script type=”text/javascript”>
if(window.localStorage){
//存储
localStorage.name=”张三”;/
localStorage[“age”]=23;
localStorage.setItem(“sex”,”男”);
//获取
console,log(localStorage.name);
console.log(localStorage[“age”]);
console.log(localStorage.getItem(“sex”));
}
</script>
//上面这三种方法的结是存储：name：张三;age:23;sex男,存储了三条简单信息；
localStorage.length//返回当前本地存储的条数
上面我们存储了三条信息，则localStorage.length就为3；
localStorage.key();//返回当前存储的键的内容
对于上面我们存储的三条信息：
localStorage.key(0);//则返回name
localStorage.key(1);//则返回age[align=center][/align]
我们可以用for循环来一一列出
<script type=”text/javascript”>
if(window.localStorage){
for(var i=0;i<localStorage.length;i++){
console.log(localStorage.key(i),localStorage.getItem(localStorage.key(i)));
}
}
//结果为name：张三;age:23;sex男
</script>
***注意，localStorage处理的都是字符串类型的数据,在处理复杂的数据类型时，比如JSON数据,就需要用到JSON的方法***：下面我们举个例子
假如我们要存储一个JSON对象
Person=[{"id":"01","name":"张三","age":"25","sex":"男"},{"id":"02","name":"李四","age":"25","sex":"女"},{"id":"03","name":"王五","age":"1","sex":"女"}];
需要用到JSON.stringify();方法把JSON对象序列化为一个字符串，再进行存储
localStorage.setItem(“person”,JSON.stringify(Person));
获取时，我们需要用到JSON.parse()方法;再把它转为JSON对象，我们就可以取出
完整的存取代码如下：
<script type=”text/javascript”>
if(window.localStorage){
Person=[{"id":"01","name":"张三","age":"25","sex":"男"},{"id":"02","name":"李四","age":"25","sex":"女"},{"id":"03","name":"王五","age":"1","sex":"女"}];
//存储
localStorage.setItem(“person”,JSON.stringify(Person));
for(var i=0;i<localStorage.length;i++){
if(localStorage.key(i)==”person”){
var data=JSON.parse(localStorage.getItem(localStorage.key(i)));
for(var j=0;i<data.length;j++){
console.log(data[i].id+”,”+data[i].name+”,”+data[i].age+”,”+data[i].sex);
}
}
}

}
</script>
//这样就完成了json对象的存储。