js获取当前时间或者n天后的时间

getDateXHL(num) {
    var date = new Date();
    var dateNumber = date.getTime();
    var differ = num * 24 * 60 * 60 * 1000;
    var needDateNumber = new Date(dateNumber + differ);
    var year = needDateNumber.getFullYear();
    var month = needDateNumber.getMonth() + 1;
    var day = needDateNumber.getDate();
    var monthX = month < 10 ? "0" + month : month;
    var dayX = day < 10 ? "0" + day : day;
    var nowDate = year + "-" + monthX + "-" + dayX;
    return nowDate;
}

//获取7天之前日期
var aaa = getDateXHL(-7);
//获取当前日期
var bbb = getDateXHL(0);
//获取30天之后日期
var ccc = getDateXHL(30);