Determining Date Equality in Javascript

问题

I need to find out if two dates the user selects are the same in Javascript. The dates are passed to this function in a String ("xx/xx/xxxx").That is all the granularity I need.

Here is my code:

        var valid = true;
    var d1 = new Date($('#datein').val());
    var d2 = new Date($('#dateout').val());
    alert(d1+"\n"+d2);
    if(d1 > d2) {
        alert("Your check out date must be after your check in date.");
        valid = false;
    } else if(d1 == d2) {
        alert("You cannot check out on the same day you check in.");
        valid = false;
    }

The javascript alert after converting the dates to objects looks like this:

Tue Jan 25 2011 00:00:00 GMT-0800 (Pacific Standard Time)

Tue Jan 25 2011 00:00:00 GMT-0800 (Pacific Standard Time)

The test to determine if date 1 is greater than date 2 works. But using the == or === operators do not change valid to false.

回答1:

Use the getTime() method. It will check the numeric value of the date and it will work for both the greater than/less than checks as well as the equals checks.

EDIT:

if (d1.getTime() === d2.getTime())

回答2:

If you don't want to call getTime() just try this:

(a >= b && a <= b)

回答3:

var d1 = new Date($('#datein').val());
var d2 = new Date($('#dateout').val());

use two simple ways to check equality

1. if( d1.toString() === d2.toString())
2. if( +d1 === +d2)

来源：https://stackoverflow.com/questions/4587060/determining-date-equality-in-javascript