<?php
$data=array('1','2','3','4','5','6','7','8','9','10','11');
$class="one";
foreach ($data as $k=>$elem){
$idiv=renderdiv($elem,true);
if ($class=="one" || $class=="two" && isset($buffer)){
if ($class=="two"){
$idiv=$buffer.$idiv;
unset($buffer);
}
renderdiv($idiv,false,$class);
$class=($class=="one" ? "two" : "one");
}else{
$buffer=$idiv;
}
}
if ($class=="two" && isset($buffer)){
renderdiv($buffer,false,$class);
}
function renderdiv($content,$return=false,$class=""){
$div="<div" . (empty($class) ? "" : " class='".$class."'") . ">";
$div.=$content."</div>";
if ($return){
return $div;
}
echo $div;
}