递归？是不是太费力了！
倒序循环数组！

$array = range(1,10);
end($array);
while($key = key($array)){
if(!isset($ar))
{
		$ar = array($key=>current($array));
		prev($array);
	}else{
		$ar = array($key=>$ar);
		prev($array);
	}
}
print_r($ar);

结果为

Array
(
    [1] => Array
        (
            [2] => Array
                (
                    [3] => Array
                        (
                            [4] => Array
                                (
                                    [5] => Array
                                        (
                                            [6] => Array
                                                (
                                                    [7] => Array
                                                        (
                                                            [8] => Array
                                                                (
                                                                    [9] => 10
                                                                )

                                                        )

                                                )

                                        )

                                )

                        )

                )

        )

)