RedBlueThing RedBlueThing - 1 year ago 57
PHP Question

How do I compare two DateTime objects in PHP 5.2.8?

This seems like something that should be pretty straight forward, but I have been stuck page faulting this problem for a while now, so here goes.

Having a look on the PHP documentation , the following two methods of the DateTime object would both seem to solve my problem:

Both these methods are marked in the doco as being available in version >= 5.3 (and, not surprisingly, if I try to call them I find they don't exist). I can't find any specific documentation for 5.2.8 so I am not sure if there are equivalent methods in my version. I have Googled the problem and found an eclectic range of solutions, none of which answer my very simple requirements:

  • How do I compare two DateTime objects?

  • Where can I find the doco for previous PHP versions? Specifically version 5.2.8?

For some context, I have the following code:

$st_dt = new DateTime(verifyParam ('start_date'));
$end_dt = new DateTime(verifyParam ('end_date'));

// is the end date more ancient than the start date?
if ($end_dt < $start_dt)

Apparently there is no comparison operator on this guy.

EDIT: Apparently my assumptions were completely false (thanks Milen for illustrating this so effectively). There is a comparison operator and it works just fine thanks. Sometimes I really miss a compiler. The bug is in the code above, I am sure you will find it much faster than I did :).

I look forward to my embarrassment at the simplicity of your solution.

EDIT: And sure enough, embarrassment ensues ...

Answer Source

The following seems to confirm that there are comparison operators for the DateTime class:

dev:~# php

$d1 = new DateTime('2008-08-03 14:52:10');
$d2 = new DateTime('2008-01-03 11:11:10');
var_dump($d1 == $d2);
var_dump($d1 > $d2);
var_dump($d1 < $d2);
dev:~# php -v
PHP 5.2.6-1+lenny3 with Suhosin-Patch (cli) (built: Apr 26 2009 20:09:03)
Copyright (c) 1997-2008 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2008 Zend Technologies