It really works?

try it:
Date.prototype.isLeapYear = function(year) {
if (year == null) { year = this.getFullYear() }
return (year < 1601 && year % 4 == 0) ||
(year % 400 == 0 && year % 100 != 0) ||
year % 4 == 0 ? true : false;
}

usage:

t = new Date();
trace(t.isLeapYear(2004)); // true
trace(t.isLeapYear()); // false (2002)

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No MSA, your logic is flawed my friend.

Here is the REAL WORKING leap year prototype is:


Date.prototype.leapYear = function ( year ) { if (year == null) { year = this.getFullYear() } return (((year % 4 == 0) && (year % 100 != 0)) || (year % 400 == 0)) ? 1 : 0; }


You see, you have to check if the year is divisible by 4 and NOT 100, or the year is divisible by 400.
You had divisible by 4 passing through (and you were checking if the year was divisible by 400 and not 100 ... which would never be true of course)

-chicken

Date.prototype.getLeapYear = function() { return ((new Date(this.getFullYear(), 2, 0).getDate()) == 29 ? 1 : 0); }; // Usage datum = new Date(); trace("Leapyear: " + datum.getLeapYear());


Have fun!

Madokan, your code is not working went come to year 2000!!

Hi alfgear - getLeapYear works fine 2000 was a leapyear! :)