Compare dates with javascript [duplicate]

Question

I have two dates in javascript:

var first = '2012-11-21';
var second = '2012-11-03';

i would like make:

 if(first > second){
   //...
 }

how is the best way for this, without external library?

Answer 1

if( (new Date(first).getTime() > new Date(second).getTime()))
{
    ----------------------------------
}

Answer 2

If your dates are strings in a strict yyyy-mm-dd format as shown in the question then your code will work as is without converting to date objects or numbers:

if(first > second){

...will do a lexographic (i.e., alphanumeric "dictionary order") string comparison - which will compare the first characters of each string, then the second characters of each string, etc. Which will give the result you want...

Answer 3

You can do this way, it will work fine:

var date1 = new Date('2013-07-30');
var date2 = new Date('2013-07-30');

if(date1 === date2){ console.log("both are equal");}  //it does not work 
==>undefined  //result
if(+date1 === +date2){ console.log("both are equal");} //do it this way! 
//(use + prefix for a variable that holds a date value)
==> both are equal //result

Note :- don't forget to use a + prefix