JS獲取當前日期加10天后的日期，轉換成XXXX-XX-XX 格式

var nowDateObj = new Date();
var nowTimeStem = nowDateObj.getTime();
var endTimeStem = nowTimeStem + 24*60*60*1000*10;
var endDateObj = new Date(endTimeStem);
var month = endDateObj.getMonth() + 1;
month = month>10?month:'0'+month;
var day = endDateObj.getDate();
day = day>10?day:'0'+day;
endDateStr = endDateObj.getFullYear() +'-'+month+'-'+day;