用JavaScript比较不同格式的日期

Question

I'm attempting to compare 2 dates that have 2 different formats in Javascript.

The date from my database is 2013-04-21 (date1) and the date in the array prints out in the following format in my Chrome debugger: Sun Apr 21 2013 15:37:05 GMT-0400 (Eastern Daylight Time) (date2)

I'd like to compare only the date part and leave out the time: date1 == date2 is true.

How would I go about formatting the dates so I'd be able to compare them?

Any help is greatly appreciated.

Answer 1

y = date2.getFullYear();
m = date2.getMonth()+1;
m = (m<10)? ('0'+m) : m;
d = date2.getDate();
d2 = y+'-'+m+'-'+d;

if (date1 == d2) {
  // do something
}

Answer 2

date1.toISOString().split("T")[0] == date2.toISOString().split("T")[0]

Answer 3

We have to go a little deeper here: we have to distinguishe between Strings storing date, and the Date object which can store dates and do computation with dates.

From your description i guess that date1 is acutally a string "2013-04-21" while date2 is already a Date object.

You could convert date1 to a date object:

date1AsObject = new Date("2013-04-21");

Then you could compute the difference between them:

diff = date2 - date1AsObject

the result will be in milliseconds.

or you could convert date2 to a string like Crayon Violent suggested:

y = date2.getFullYear();
m = date2.getMonth()+1;
d = date2.getDate();
date2AsString = y+'-'+m+'-'+d;

then you can compare the two strings.