php - Variable vs. Text Subtraction

Magic Monkey

I've just started doing some simple php, and want to know is it possible to subtract a "text-value" (for want of a better term) from a variable, i.e.

<td><center>31/1</center></td>

I have the date 31st of Janurary in a table column (as above), and I have another variable called "$mday" ( from getdate() ) which holds today's date in numerical format, e.g. 22

So, if I declare a new variable "$total", how do I initalise it do subtract $mday from 31? Or is that even possible?

If it's not possible, no problem, as I can just declare 31 as a variable, but I'm curious now just to see if this can be done

Balfa

i don't quite get what you want to do.

if you want to initialise $total as 31 - $mday, wouldn't you just do $total = 31 - $mday?

*boggle*

Magic Monkey

Yes, thanks, that actually makes more sense to use now, d'oh!

But what I meant originally was could you point to the table column that contains the text-value instead of explicitly typing it, e.g.

$total = $name - $mday
Where "$name" would be the name of the table column (um, that is, if you could name it).

You know, I'm probably just making a mountain out of a molehill here

Balfa

i'm not sure if you can do _that_, but you could define that as another variable, so you can have something like:

$tabledate = 31
<td><center><? $tabledate ?>/1</center></td>
// the above line will insert the value for tabledate in
// where you manually typed 31 before
$total = $tabledate - $mday


that any help?

Magic Monkey

Originally posted by Balfa
i'm not sure if you can do _that_, but you could define that as another variable, so you can have something like:

$tabledate = 31
<td><center><? $tabledate ?>/1</center></td>
// the above line will insert the value for tabledate in
// where you manually typed 31 before
$total = $tabledate - $mday


that any help?

Heh, funnily enough that's what I ended up doing just a few minutes ago
Except that the $tabledate is "31/1" in my code, and when I do $tabledate - $mday (22) I get 9, which is right. It must ignore the /1 for some reason.

While you're here, you don't know anything about date subtraction, do you?

The Corinthian

Originally posted by Magic Monkey
While you're here, you don't know anything about date subtraction, do you?

You may find the mktime useful for that. Otherwise I would reccomend you avoid using datetime types such as MySQL DATETIME and use only UNIX timestamps.

Beyond that, you should RTFM on PHP Date/Time functions. Hope this helped.

Magic Monkey

Originally posted by The Corinthian
You may find the mktime useful for that. Otherwise I would reccomend you avoid using datetime types such as MySQL DATETIME and use only UNIX timestamps.

Beyond that, you should RTFM on PHP Date/Time functions. Hope this helped.

Thanks Corinthian,

I found a good tutorial here, that I'm reading ATM. Yeah, DATETIME wouldn't be appropriate in this case, and time() seems to be extremley flexible, so it's all cool.