How to determine php array dimensions (php array length)

/**
 * Return the dimensions of the array
 * @param [type] $arr [description]
 * @return [type] [description]
*/ bbs.it-home.org
function arrayLevel($arr){
    $al = array(0);
    function aL($arr,&$al,$level=0){
        if(is_array($arr)){
            $level++;
            $al[] = $level;
            foreach($arr as $v){
                aL($v,$al,$level);
            }
        }
    }
    aL($arr,$al);
    return max($al);
}
$arr = array(
    '0'=>'0',
);
echo arrayLevel($arr);
?>