当两个for循环嵌套的时候，如何运行的

Question

后端给我了一个开始时间和一个结束时间，我需要判断是否在这个时间段内。首先开始时间和结束时间可能会是多个数组，时间段也会是多个数据。数据结构如下{"code":"0","data":{"nowDate":"2018-09-03 14:25:57","isCanUpdate":"0","list":[{"times":[{"startTime":"09:00","endTime":"21:30"}],"day":"2018-09-17"},{"times":[{"startTime":"09:00","endTime":"21:30"}],"day":"2018-09-18"},{"times":[{"startTime":"09:00","endTime":"21:30"}],"day":"2018-09-19"},{"times":[{"startTime":"09:00","endTime":"21:30"}],"day":"2018-09-20"},{"times":[{"startTime":"09:00","endTime":"21:30"}],"day":"2018-09-21"},{"times":[{"startTime":"09:00","endTime":"21:30"}],"day":"2018-09-22"},{"times":[{"startTime":"09:00","endTime":"21:30"}],"day":"2018-09-23"}]},"info":"成功"}这是我处理过的数据computed:{              newTimesList(){                  var day = this.childmessage.day                  var newTimesList=this.initTimesList.map(function(item) {                      return +new Date((day+" "+item).replace(/-/g,"/"));                  })                  return newTimesList              },              getTime(){                  var timeLength = this.times.length;                  var timesArray = [];                  for (var i = 0; i < timeLength; i++) {                      var startTime = this.day+" "+this.times[i].startTime;                      var endTime = this.day+" "+this.times[i].endTime;                      var startTimeStr = +new Date(startTime.replace(/-/g,"/"));                      var endTimeStr = +new Date(endTime.replace(/-/g,"/"));                      var timesList = {                          startTimeStr:startTimeStr,                          endTimeStr : endTimeStr                      }                      timesArray.push(timesList)                      return timesArray                  }              },我想根据最后这个数据的下标判断有没有active这个类