Problem with dynamic color background

Joram

I have created a PHP based guestbook, and now I want each even entry (record) to have a black background and each odd entry should have a grey background, to distinguish the entries.

To test it, I've used [echo bckground="FFFFFF" if ID is 2] so I can test it. This is the code I used:
[FONT=courier new]<table width="90%" border="0"
<?php
$id = $row_Recordset1['ID'];
if ($id = 2) {echo "bgcolor="#FFFFFF""; }?> >[/FONT]
but it's giving an error. Does anybody know why?

My second question is: what do I have to put in the code in stead of the 2 to have the even in one and the odd in another color? In other words, how can I do things with even and odd integers?

_SuperString

I can spot 2 errors (is this a competition ?)

first error:
if ($id = 2)
should be
if ($id ==2) (notice the == comparison operator)

second error:
echo "bgcolor="#FFFFFF"";
should be
echo 'bgcolor="#FFFFFF"'; (notice single quotes)
or it could be a number of other variation, but I will not go into them here.

jesus_hairdo

First of all the

if ($id = 2)
..

should be

if ($id==2)
..

To work out if an $id is even, do something like

if (fmod($id, 2) == 0)
{
    ?> bgcolor='#ffffff'<? //this is an even number
}
else
{
    ?> bgcolor='#000000#'<? //this is an odd number
}

fmod is the modulus function, it basically gives you the remainder when dividing the 1st number by the 2nd number.

So if a number is even it is divisible exactly by 2, and therefore has a remainder of 0. An odd number has a remainder.

So we are saying, if $id/2 has no remainder then it is even, so display that colour,
else it must be odd, so have it as a different colour.

Jamie

Weedpacket

Originally posted by jesus_hairdo
fmod is the modulus function, it basically gives you the remainder when dividing the 1st number by the 2nd number.

And is a floating-point analogue of the % operator (hence the "fmod"). Using the % in this case would be a lot faster, and possibly more accurate, too.

jesus_hairdo

I knew there was a shorter version of a mod operator, but couldn't remember off the top of my head.

Ta,

Jamie

Joram

again, I have a problem

when I use the following code:
[FONT=courier new]if (fmod($id, 2) == 0)[/FONT], I get an error:
[FONT=courier new]Call to undefined funtion: fmod()[/FONT]
does this mean that my Apache can not use this function? I have PHP version 4, Zend engine 1.1.1
-edit- nevermind i see i need a newer version in deed -edit-

My other problem:

And is a floating-point analogue of the % operator (hence the "fmod"). Using the % in this case would be a lot faster, and possibly more accurate, too.

I don't know a lot about PHP, I just started and never learnt anything about it, just started to make a guestbook and it worked. Could anyone explain this to me like I'm a six year old?

thanks

diego25

fmod works with floating point numbers (e.g 5.677), but % works with integers (e.g. 5) So, even in paper, what is faster? division (or modulus, they both take the same time) of floating point numbers or division of integers? Integers, of course.

Diego

Joram

So where do I put the %? In stead of fmod?

diego25

Instead of
if (fmod($id, 2) == 0)
use
if ($id % 2 == 0)

Diego