其实也没太大难度，主要注意设置cookie的时候需要统一path，因为现在很多pathinfo模式的url，会导致path不统一，你在 www.domain.com/foo 路径下设置的cookie在www.domain.com/bar下可能会读取不到，因为path可能不同，默认 / 最好

//增加或者更新cookiefunction setCookie(c_name, value, expiredays, path) {    var expiredays = arguments[2] ? arguments[2] : 1;    var path = arguments[3] ? arguments[3] : '/';    console.log(expiredays, path);    var exdate = new Date();    exdate.setDate(exdate.getDate() + expiredays * 24 * 60 * 60 * 1000);    document.cookie = c_name + "=" + escape(value) +    ((expiredays == null) ? "" : ";expires=" + exdate.toGMTString() + ";path=" + path);}//获取cookiefunction 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 "";}//删除cookiefunction delCookie(c_name, path) {    var path = arguments[1] ? arguments[1] : '/';    var exp = new Date();    exp.setTime(exp.getTime() - 1);    var cval = getCookie(c_name);    if (cval != null) document.cookie = c_name + "=" + cval + ";expires=" + exp.toGMTString() + ";path=" + path;}

setCookie("name", "sallency");getCookie("name");delCookie("name");