获取当前月的第一天和最后一天

export function getRaceTime(){
  var year= new Date().getFullYear()
  var m= new Date().getMonth() + 1
  var date=year+'-'+m;
  var month=date.substring(5,date.length);
  //获取本月的第一天日期
  var firstdate = toNum(month) + '.' +'01';
  var day = new Date(year,month,0);
  //获取本月最后一天日期
  var lastdate = toNum(month) + '.' + day.getDate();
  var raceDate=firstdate+'-'+lastdate

  return {
    m,
    raceDate
  }
}
function toNum(num){
  if(num>10){
    return num
  }else{
    return '0'+num
  }
}