js 读写cookie

/*
*以下代码只是网上收集备用
*/
//添加cookie
function addCookie(objName, objValue, objHours) {//添加cookie
    var str = objName + "=" + escape(objValue);
    if (objHours > 0) {//为0时不设定过期时间，浏览器关闭时cookie自动消失
        var date = new Date();
        var ms = objHours * 3600 * 1000;
        date.setTime(date.getTime() + ms);
        str += "; expires=" + date.toGMTString();
    }
    document.cookie = str;
    alert("添加cookie成功");
}
//读取cookie
function getCookie(objName) {//获取指定名称的cookie的值
    var arrStr = document.cookie.split("; ");
    for (var i = 0; i < arrStr.length; i++) {
        var temp = arrStr[i].split("=");
        if (temp[0] == objName) return unescape(temp[1]);
    }
}
//删除cookie
function delCookie(name) {//为了删除指定名称的cookie，可以将其过期时间设定为一个过去的时间
    var date = new Date();
    date.setTime(date.getTime() - 10000);
    document.cookie = name + "=a; expires=" + date.toGMTString();
}

//读取所有cookie
function allCookie() {//读取所有保存的cookie字符串
    var str = document.cookie;
    if (str == "") {
        str = "没有保存任何cookie";
    }
    alert(str);
}