[Phpwm] days_between()

[Paul Matthews]

On 07/06/07, Phil Beynon <phil at infolinkelectronics.co.uk> wrote:
>
> This might come in useful to someone, it takes a mysql datetime field and
> tells you how many days between it and either another datetime field or
> formatted date() YYYY-MM-DD HH:MM:SS in a signed manner.
> Its pretty flexible about data input and will return an X if it doesnt
> like
> incoming data.


Sounds like a good idea, but the idea of using 'return "x"' as an
error is, in my mind, a really bad idea. if you were using PHP4 I'd
have returned 'NULL' or something that made more sense, if you were
using PHP5 then I'd have thrown an exception of some kind.


function days_between($a,$b){
> $aa = explode(" ",$a); $ab = explode("-",$aa[0]);
> $ba = explode(" ",$b); $bb = explode("-",$ba[0]);
> if(@checkdate($ab[1],$ab[2],$ab[0]) AND @checkdate($bb[1],$bb[2],$bb[0])){
> $a_bits = getdate(strtotime($a));
> $b_bits = getdate(strtotime($b));
> $a_new = mktime(12,0,0,$a_bits['mon'],$a_bits['mday'],$a_bits['year']);
> $b_new = mktime(12,0,0,$b_bits['mon'],$b_bits['mday'],$b_bits['year']);
> if($a_new > $b_new){return 0 - round(abs($a_new - $b_new)/86400);}
> return round(abs($a_new - $b_new)/86400);
> } else return "X";
> }


The other thing that I'm lead to believe is bad coding practise is the use
of the '@' symbol. I can understand not wanting to see the errors, but
surely you should be catching them and dealing with them or let them bubble
out so that the layer above can catch them.
Finally perhaps a more suitable naming convention for your variables might
assist other programmers and readability in the future.

>From Paul M.