对js cookie的一些理解

创建cookie

//cname  设置cookie的名称//cvalue 设置cookie的值//exdays 设置cookie过期天数function setCookie(cname,cvalue,exdays) {    var d = new Date();    d.setTime(d.getTime()+(exdays*24*60*60*1000));    var expires = "expires="+d.toGMTString();    document.cookie = cname + "=" + cvalue + "; " + expires;} 

获取cookie

function getCookie(cname) {    var name = cname + "=";    var ca = document.cookie.split(';');    for(var i=0; i<ca.length; i++) {          var c = ca[i].trim();    if (c.indexOf(name)==0) {        return c.substring(name.length,c.length);    }  }    return "";} 

删除cookie

function delCookie(name){//删除cookie    var exp = new Date();    exp.setTime(exp.getTime() - 1);    var cval=getCookie(name);    if(cval!=null)    document.cookie= name + "="+cval+";expires="+exp.toGMTString();}