php循环,该怎么解决

$arr = array(
    'https://www.gxlcms.com/images/small_case_1.jpg',
    'https://www.gxlcms.com/images/small_case_2.jpg',
    'https://www.gxlcms.com/images/small_case_3.jpg',
    'https://www.gxlcms.com/images/small_case_4.jpg',
    'https://www.gxlcms.com/images/small_case_5.jpg',
    'https://www.gxlcms.com/images/small_case_6.jpg',
    'https://www.gxlcms.com/images/small_case_7.jpg',
    'https://www.gxlcms.com/images/small_case_8.jpg',
    'https://www.gxlcms.com/images/small_case_9.jpg'
);

function arr2li($arr){
    $html  = '';
    if(is_array($arr) && !empty($arr)){
        $count = count($arr);
        for($i=0; $i<$count; $i++){
            $rem = $i%3;
            $html .= ($i!=0 && $rem==0) ? "\n\r\n\r" : "";
            $html .= ($rem==0) ? "
\n\r
\n\r" : "";
            $html .= sprintf("
\n\r", $arr[$i]);
            $html .= ($i+1==$count) ? "
\n\r
" : "";
        }
    }
    return $html;
}

/*










































*/

echo arr2li($arr);

$result=mysql_query("select * from case_list"); 
while($row=mysql_fetch_assoc($result)){
       $ar[]=$row;
}
foreach(array_chunk($ar,3) as $v){
    echo "
\n
\n";
	foreach($v as $vl) echo "
\n";
	echo "
\n
\n";
}