Js清空cookie

//清空cookie
function clearCookie() {
   var keys = document.cookie.match(/[^ =;]+(?=\=)/g);
   console.log(keys);
   if (keys) {
      for (var i = keys.length; i--;) {
            document.cookie = keys[i] + '=0;path=/;expires=' + new Date(0).toUTCString();//清除当前域名下的,例如：m.kevis.com
            document.cookie = keys[i] + '=0;path=/;domain=' + document.domain + ';expires=' + new Date(0).toUTCString();//清除当前域名下的，例如 .m.kevis.com
            document.cookie = keys[i] + '=0;path=/;domain=kevis.com;expires=' + new Date(0).toUTCString();//清除一级域名下的或指定的，例如 .kevis.com
      }
   }
   console.log('已清除cookie'); 
}

function getCookie(c_name)
{
if (document.cookie.length>0)
  {
  c_start=document.cookie.indexOf(c_name + "=")
  if (c_start!=-1)
    { 
    c_start=c_start + c_name.length+1 
    c_end=document.cookie.indexOf(";",c_start)
    if (c_end==-1) c_end=document.cookie.length
    return unescape(document.cookie.substring(c_start,c_end))
    } 
  }
return ""
}