js学习cookie封装之添加

 1 添加cookie
 2 function setCookie(name,value,expires,domain){
 3           var cookie = name + '=' + value;
 4           //有失效日期时
 5           if(expires){
 6                  cookie +=';expires' +expires
 7           }
 8 
 9            //有域名限制时
10           if(domain){
11                  cookie += ';domain' + domain
12          }      
13       
14           //写入cookie
15           document.cookie = cookie;    
16 }