php: how to add odd/even loop in array - php

Question

here is my code: http://www.pcgage.net/code.zip (sorry, pasting the code caused it to really mess up, even using the code container).
Scroll to line: 160 (to 174) - this is the loop in question. i want to make it so this is the even part, and then some code to make an odd part, so the loop repeats in this order. The reason is that i want to change the content of this loop alternately.
I am not a coder, so the best thing you could do is to post up the new code and i'll add it in where you tell me too, otherwise i'll get lost :)
Hope that makes sense, if not you can check an earlier post about this issue that explains why i need this (after finding out that css alone cannot solve my problem): css/php: how to solve this div float problem / odd even loop in array
this is the loop:
} elseif ( ( $findpost->ID ) != $id ) {
// all other posts except the current post
$serp_list_li[] = '<div class="serial-contain">
<div class=""><h5>' . $findpost->post_title . '</h5></div>
<div class="text-align">' . $findpost->post_excerpt . ' </div>
<div class="date"> ' . mysql2date('M jS, Y', $findpost->post_date) . ' at ' . mysql2date('g:ia', $findpost->post_date) . '</div>
<div class="comments"><b>' . $findpost->comment_count . ' Comments</b></div>
</div>' . "\n";
}
else {

Answer 1

The three ways are
Modulo
for ($i = 0; $i < 10; $i++)
{
if ($i % 2 == 0)
{
echo "even";
}
else
{
echo "odd";
}
}
Flipping boolean value
$even = true;
for ($i = 0; $i < 10; $i++)
{
if ($even)
{
echo "even";
}
else
{
echo "odd";
}
$even = !$even;
}
And mentioned boolean operator
for ($i = 0; $i < 10; $i++)
{
if ($i & 1 == 0)
{
echo "even";
}
else
{
echo "odd";
}
}
The most fastest is boolean operator. But the most robust is flipping method if you have very different numbers (like running through ID numbers and some are missing).

Answer 2

I haven't looked over the code, but if it's using a variable to count the loop number you can do:
for($i=0;$i<$blah;$i++)
if($i&1){
// ODD
}else{
// EVEN
}
EDIT(1):
I looked at the section you are running into, and now I have another problem, I'm unsure how you are judging what should be odd or not, so I propose two answers:
1: odd loop itteration:
/* Populate the post list array */
// Add here:
$oddLoop = false;
foreach ($findposts as $findpost):
//.....
if($oddLoop=!$oddLoop){
// code for odd loop numbers
}else{
// code for even loop numbers
}
2: Odd ID number:
} elseif ( ( $findpost->ID ) != $id ) {
if($findpost->ID & 1){
// ODD
}else{
//EVEN
}

Answer 3

For loops increment by 1:
$state = 'odd';
for (...)
{
$state = ($state == 'even' ? 'odd' : 'even');
echo $state . PHP_EOL;
}
Output:
even
odd
even
odd
...

Answer 4

If you ever delete an article you could be in trouble - your code assumes that ID runs (odd,even,odd,even) etc.
A better idea would be to create a separate iterator object to feed you the necessary values at each step. Here's what I use:
class LoopingPropertyIterator implements Iterator
{
private $startat = 0, $position = 0;
private $propertylist = array(
'boolean' => array(false, true),
'day' => array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'),
'dow' => array('Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat')
);
public function __construct($args, $startat = 0)
{
$this->startat = (int)$startat;
$this->position = $this->startat;
foreach ($args as $name => $arr)
$this->__set($name, $arr);
}
public function __get($name)
{
if (!array_key_exists($name, $this->propertylist))
throw new Exception(__METHOD__ . " unknown property $name");
$t =& $this->propertylist[$name];
if (is_array($t))
return $t[$this->position % count($t)];
else
return $t;
}
public function __set($name, $arr)
{
$this->propertylist[$name] = $arr;
}
public function current()
{
return $this->position;
}
public function key()
{
return $this->position;
}
public function next()
{
++$this->position;
}
public function rewind()
{
$this->position = $this->startat;
}
public function valid()
{
return true;
}
}
then your output simplifies to
$iter = new LoopingPropertyIterator( array(
'outerclass' => array('serial-contain-right','serial-contain-left'),
'innerclass' => array('text-align2','text-align')
));
...
elseif ( $findpost->ID != $id ) {
$link = get_permalink($firstpost->ID);
$title = $findpost->post_title;
$datetime = mysql2date('M jS, Y', $findpost->post_date).' at '.mysql2date('g:ia', $findpost->post_date);
$serp_list_li[]=
<<<TEXT
<div class="{$iter.outerclass}">
<div class="title">
<h5>{$title}</h5>
</div>
<div class="{$iter->innerclass}">{$findpost->excerpt}</div>
<div class="date">{$date}</div>
<div class="comments">
<a href="{$link}#comments"> title="{$title}">
<b>{$findpost->comment_count} Comments</b>
</a>
</div>
</div>
TEXT;
$iter->next();
}

Answer 5

Are you sure $findpost->ID contains sequential numbers?
You could replace the if/else with s short ternary statement like this:
$side = empty($side) || $side == 'right' ? 'left' : 'right';
$serp_list_li[] = '<div class="serial-contain-' . $side . '">' // ...the rest
This would add a 'left' side first.

Answer 6

Get EvenArray and OddArray
NSArray *numberArray = [NSArray arrayWithObjects:#1,#2,#3,#4,#6,#8,#10, nil];
for (id object in numberArray)
{
if ([object integerValue] % 2 == 0)
{
[evenArray addObject:object];
}
else
{
[oddArray addObject:object];
}
}