js 設(shè)置 cookie的時(shí)候，默認(rèn)會(huì)存放在當(dāng)前域名下，如果想要在子域名之間共享，
如a.example.com下設(shè)置cookie彼硫， 在b.example.com下使用，
需要如下設(shè)置：
var Cookie =
{
set: function(name, value, days)
{
var domain, domainParts, date, expires, host;
if (days)
{
date = new Date();
date.setTime(date.getTime()+(days*24*60*60*1000));
expires = "; expires="+date.toGMTString();
}
else
{
expires = "";
}
host = location.host;
if (host.split('.').length === 1)
{
// no "." in a domain - it's localhost or something similar
document.cookie = name+"="+value+expires+"; path=/";
}
else
{
// Remember the cookie on all subdomains.
//
// Start with trying to set cookie to the top domain.
// (example: if user is on foo.com, try to set
// cookie to domain ".com")
//
// If the cookie will not be set, it means ".com"
// is a top level domain and we need to
// set the cookie to ".foo.com"
domainParts = host.split('.');
domainParts.shift();
domain = '.'+domainParts.join('.');
document.cookie = name+"="+value+expires+"; path=/; domain="+domain;
// check if cookie was successfuly set to the given domain
// (otherwise it was a Top-Level Domain)
if (Cookie.get(name) == null || Cookie.get(name) != value)
{
// append "." to current domain
domain = '.'+host;
document.cookie = name+"="+value+expires+"; path=/; domain="+domain;
}
}
},
get: function(name)
{
var nameEQ = name + "=";
var ca = document.cookie.split(';');
for (var i=0; i < ca.length; i++)
{
var c = ca[i];
while (c.charAt(0)==' ')
{
c = c.substring(1,c.length);
}
if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
}
return null;
},
erase: function(name)
{
Cookie.set(name, '', -1);
}
};
調(diào)用方法：
Cookie.set('test', '123');
