js:

    function set_cookie(key, val,now){

        var exdate = new Date(now);

        exdate.setDate(exdate.getDate() + 30);

        exdate = exdate.toGMTString();

        document.cookie = key +　'=' + val + ";path=/;domain=;expires=" + exdate;

    }

    function get_cookie(key){

        var cookies = document.cookie.split(';'), val;

        for (var i = 0; i < cookies.length; i++) {

            if (cookies[i].indexOf(key) !== -1) {

                val = cookies[i].split('=')[1];

                break;

            }

        }

        return val || null;

    }

函数直接调用即可

node：

    function set_cookie(key, val){

        var exdate = new Date();

        exdate.setDate(exdate.getDate() + 30);

        exdate = exdate.toGMTString();

        return key +　'=' + val + ";path=/;domain=;expires=" + exdate;

    }

    res.setHeader("Set-Cookie", [set_cookie()]);