获取30天前的日期

获取30天前的日期，同理也可获取n天前的日期

getMothDate() {

let dateObj = {}

let endDate =new Date()

let year = endDate.getFullYear()

let month = endDate.getMonth() +1

 let day = endDate.getDate()

dateObj.end =`${year}-${month <10 ?'0' + month : month}-${day <10 ?'0' + day : day}`

  // 获取三十天前日期

  let startDate =new Date(endDate -1000 *60 *60 *24 *30)// 最后一个数字30可改，30天的意思

  let lastY = startDate.getFullYear()

let lastM = startDate.getMonth() +1

  let lastD = startDate.getDate()

dateObj.start =`${lastY}-${lastM <10 ?'0' + lastM : lastM}-${lastD <10 ?'0' + lastD : lastD}`

  return dateObj

},