const curDate = new Date();//获取当前时间
var datetime = new Date(curDate.getTime() - 24*60*60*1000); //获取前一天的时间
var year=datetime.getFullYear(); //获取当前年份
var month=datetime.getMonth()+1; //获取当前月份
if(month<=9){
month="0"+month;
}
var date=datetime.getDate(); //获取当前时间
if(date<=9){
date="0"+date;
}
cosnt startDate = year+"-"+month+"-"+date
输出结果:2021-04-05