搜索日期数组总是返回-1

Question

我已经为去年创建了一个日期数组，我需要在给定日期的数组中找到索引，但它返回-1

然而，如果我硬编码不好的日期，因为它不是动态的，它可以工作并输出331，这是我所期待的

我该怎么做才能让它发挥作用？

// Returns an array of dates between the two dates
var getDates = function(startDate, endDate) {
  var dates = [],
    currentDate = startDate,
    addDays = function(days) {
      var date = new Date(this.valueOf());
      date.setDate(date.getDate() + days);
      return date;
    };

  while (currentDate <= endDate) {
    dates.push(currentDate);
    currentDate = addDays.call(currentDate, 1);
  }
  return dates;
};

var today = new Date(),
  last_year = new Date();

last_year.setMonth(last_year.getMonth() - 12);
last_year.setDate(last_year.getDate() + 1);

var dates = getDates(last_year, today);

var d = new Date(2017, 10, 31);

var test = dates.map(Number).indexOf(+d);
console.log(test); // dump -1

这有效.....

dates = getDates(new Date(2017, 0, 4), new Date(2018, 12, 4));
d = new Date(2017, 10, 31);

test = dates.map(Number).indexOf(+d);
console.log(test); // dumps 331

Answer 1

由于您未将小时，分钟设置为0，因此new Date()正在当前时间戳

last_year.setMonth(last_year.getMonth() - 12);
last_year.setDate(last_year.getDate() + 1);
last_year.setHours(0,0,0,0); //this line is added

<强>演示

＆＃13;

＆＃13;

// Returns an array of dates between the two dates
var getDates = function(startDate, endDate) {
  var dates = [],
    currentDate = startDate,
    addDays = function(days) {
      var date = new Date(this.valueOf());
      date.setDate(date.getDate() + days);
      return date;
    };

  while (currentDate <= endDate) {
    dates.push(currentDate);
    currentDate = addDays.call(currentDate, 1);
  }
  return dates;
};

var today = new Date(),
  last_year = new Date();

last_year.setMonth(last_year.getMonth() - 12);
last_year.setDate(last_year.getDate() + 1);
last_year.setHours(0,0,0,0);

var dates = getDates(last_year, today);

var d = new Date(2017, 10, 31);

var test = dates.map(Number).indexOf(+d);
console.log(test);

// works

dates = getDates(new Date(2017, 0, 4), new Date(2018, 12, 4));
d = new Date(2017, 10, 31);

test = dates.map(Number).indexOf(+d);
console.log(test);

＆＃13;

＆＃13;

＆＃13;