秒客网

代码如下：

function getCookie(key){
        var cookies=document.cookie;
        if(cookies.length>0){
            var start=cookies.indexOf(key+"=");
            if(start<0){
                return "";
            }
            var end =cookies.indexOf(";",start);
            if(end<0){
                end=cookies.length;
            }
            return cookies.substring(start+key.length+1,end);
        }
    }

或者

function getCookie(cookieName) {
    var strCookie = document.cookie;
    var arrCookie = strCookie.split("; ");
    for(var i = 0; i < arrCookie.length; i++){
        var arr = arrCookie[i].split("=");
        if(cookieName == arr[0]){
            return arr[1];
        }
    }
    return "";
}

简单来说浏览器的cookie是通过document.cookie存放的格式类似于，"t=2;r=3;t=4"的形式，按照这个形式进行截取就好了