将字符串数组（每个字符串都有点分隔值）转换为多维数组

Question

我有以下数组：

Array
(
    [0] => INBOX.Trash
    [1] => INBOX.Sent
    [2] => INBOX.Drafts
    [3] => INBOX.Test.sub folder
    [4] => INBOX.Test.sub folder.test 2
)

如何将这个数组转换成这样的多维数组：

Array
(
    [Inbox] => Array
        (
            [Trash] => Array
                (
                )

            [Sent] => Array
                (
                )

            [Drafts] => Array
                (
                )

            [Test] => Array
                (
                    [sub folder] => Array
                        (
                            [test 2] => Array
                                (
                                )

                        )

                )

        )

)

Answer 1

试试这个。

<?php
$test = Array
(
    0 => 'INBOX.Trash',
    1 => 'INBOX.Sent',
    2 => 'INBOX.Drafts',
    3 => 'INBOX.Test.sub folder',
    4 => 'INBOX.Test.sub folder.test 2',
);

$output = array();
foreach($test as $element){
    assignArrayByPath($output, $element);   
}
//print_r($output);
debug($output);
function assignArrayByPath(&$arr, $path) {
    $keys = explode('.', $path);

    while ($key = array_shift($keys)) {
        $arr = &$arr[$key];
    }
}

function debug($arr){
    echo "<pre>";
    print_r($arr);
    echo "</pre>";
}

Answer 2

我对此非常感兴趣，因为尝试这样做时遇到了巨大的困难。在查看（并通过）乔恩的解决方案后，我想出了这个：

$array = array();
function parse_folder(&$array, $folder)
{
    // split the folder name by . into an array
    $path = explode('.', $folder);

    // set the pointer to the root of the array
    $root = &$array;

    // loop through the path parts until all parts have been removed (via array_shift below)
    while (count($path) > 1) {
        // extract and remove the first part of the path
        $branch = array_shift($path);
        // if the current path hasn't been created yet..
        if (!isset($root[$branch])) {
            // create it
            $root[$branch] = array();
        }
        // set the root to the current part of the path so we can append the next part directly
        $root = &$root[$branch];
    }
    // set the value of the path to an empty array as per OP request
    $root[$path[0]] = array();
}

foreach ($folders as $folder) {
    // loop through each folder and send it to the parse_folder() function
    parse_folder($array, $folder);
}

print_r($array);