Dynamically creating a multidimensional array based on paths - php

Question

So I've got a list of paths, such as:
path/to/directory/file1
path/directory/file2
path2/dir/file3
path2/dir/file4
And I'd like to convert them into a multidimensional array like this:
array(
path => array(
to => array(
directory => array(
file1 => someValue
),
),
directory => array(
file2 => someValue
),
),
path2 => array(
dir => array(
file3 => someValue,
file4 => someValue
)
)
)
My first thought was to explode() the paths into segments and set up the array using a foreach loop, something like this:
$arr = array();
foreach ( $path as $p ) {
$segments = explode('/', $p);
$str = '';
foreach ( $segments as $s ) {
$str .= "[$s]";
}
$arr{$str} = $someValue;
}
But this doesn't work, and since the number of segments varies, I've kinda got stumped. Is there away to do this?

Answer 1

If somevalue can be an empty array:
<?php
$result = array();
$input = [
'path/to/directory/file1',
'path/directory/file2',
'path2/dir/file3',
'path2/dir/file4',
];
foreach( $input as $e ) {
nest( $result, explode('/', $e));
}
var_export($result);
function nest(array &$target, array $parts) {
if ( empty($parts) ) {
return;
}
else {
$e = array_shift($parts);
if ( !isset($target[$e]) ) {
$target[$e] = [];
}
nest($target[$e], $parts);
}
}

Answer 2

Here is the solution and a easy way
Just Reverse the whole exploded array and start creating array within a Array
$path[1] = "path/to/directory/file1";
$path[2] = "path/directory/file2";
$path[3] = "path2/dir/file3";
$path[4] = "path2/dir/file4";
$arr = array();
$b = array();
$k = 0;
foreach($path as $p) {
$c = 0;
$segments = explode('/', $p);
$reversed = array_reverse($segments);
foreach($reversed as $s) {
if ($c == 0) {
$g[$k] = array($s => "somevalue");
} else {
$g[$k] = array($s => $g[$k]);
}
$c++;
}
$k++;
}
var_dump($g);

Answer 3

Thanks so much VolkerK! Your answer didn't quite answer my question but it got me on the right track. Here's the version I ended up using to get it to work:
$result = array();
$input = [
'path/to/directory/file1' => 'someValue',
'path/directory/file2' => 'someValue',
'path2/dir/file3' => 'someValue',
'path2/dir/file4' => 'someValue',
];
foreach( $input as $e=>$val ) {
nest( $result, explode('/', $e), $val);
}
var_export($result);
function nest(array &$target, array $parts, $leafValue) {
$e = array_shift($parts);
if ( empty($parts) ) {
$target[$e] = $leafValue;
return;
}
if ( !isset($target[$e]) ) {
$target[$e] = [];
}
nest($target[$e], $parts, $leafValue);
}
I basically just added the somevalue as $leafValue and moved the base case around so that it would add the leafValue instead of a blank array at the end.
This results in:
Array
(
[path] => Array
(
[to] => Array
(
[directory] => Array
(
[file1] => someValue
)
)
[directory] => Array
(
[file2] => someValue
)
)
[path2] => Array
(
[dir] => Array
(
[file3] => someValue
[file4] => someValue
)
)
)
Thanks a lot!

Answer 4

It can be done without recursion
$path = array(
'path/to/directory/file1',
'path/directory/file2',
'path2/dir/file3',
'path2/dir/file4');
$arr = [];
$someValue = 'someValue';
foreach ( $path as $p ) {
$segments = explode('/', $p);
$str = '';
$p = &$arr;
foreach ( $segments as $s ) {
if (! isset($p[$s] ) ) $p[$s] = array();
$p = &$p[$s];
}
$p = $someValue;
}
print_r($arr);