Question

I want to show all dates between two days.I can't do this.Please help.. This is my code...

 var Day = 24*60*60*1000; // hours*minutes*seconds*milliseconds
var firstDate = new Date("2017-04-10");
var secondDate = new Date("2017-04-15");

var diffDays = (secondDate.getTime() - firstDate.getTime())/Day;
alert(diffDays);
for(var i=0;i<= diffDays ;i++)
{
   var d = new Date(firstDate  + i);
   alert(d);
}

Answer 1

您的i变量是当天的数字。您的firstDate变量是Date。

这一行：

var d = new Date(firstDate + i);

将这些添加在一起并尝试创建新的Date。由于这些是不同的类型（日期和数字）类型强制起作用（即：日期和数字转换为字符串，并连接在一起）。

试试这个：

var DAY_IN_MS = 24 * 60 * 60 * 1000; // hours*minutes*seconds*milliseconds
var theDate = new Date("2017-04-10");
var i = 5;

// Date + Number = Type Coercion!  Both objects will be converted to strings and concatenated together.
alert(theDate + i);

// The Date constructor doesn't care, and will work because it can get a date from the first part of the string.
alert(new Date(theDate + i));

// If you use `getTime()` you can get the numerical value of the Date, which you can use for arithmetic.
alert(theDate.getTime());

// By adding `i`, however, you are only adding a few milliseconds to the first date !!
alert(new Date(theDate.getTime() + i);

// Number + Number of days times milliseconds per day = success!
alert(new Date(theDate.getTime() + (i * DAY_IN_MS)));

我认为你的意思是：

var d = new Date(firstDate.getTime() + (i * Day));

Answer 2

简短回答，将正确的毫秒数增加到firstDate.getTime()：

for(var i=0;i<= diffDays ;i++)
{
    firstDate = new Date(firstDate.getTime() + Day);
    console.log(firstDate);
}

答案很长，你的代码中有几个问题：

此处var d = new Date(firstDate + i);添加到Date对象字符串表示中，i的值在这种情况下在循环中递增。
然后，您将此String解析为新的Date对象，但Javascript仅识别日期并忽略附加的数字

您应该像firstDate那样尝试获得diffDays的毫秒数，然后添加i * Day（还要考虑将此变量重命名为其他内容，可能是const DAY_IN_MS或者什么）。

Show all date between two date range in javascript

2 个答案: