Nesting array elements?

Question

PHP

There is a one-dimensional array of the form

[0] => dir2
[1] => dir2_1
[2] => dir2_1_1
...

There may be one element, or there may be many.
How at the output to get them nested in each other in this way?

array(
  "dir2"=>array(
    "dir2_1"=>array(
      "dir2_1_1"=>array(...)
    )
  )
)

Answer 1

Can be recursed: https://3v4l.org/m5Cup

<?php

$input = ['dir2', 'dir2_1', 'dir2_1_1'];

function convert_array(array $input, array $output = []) {
    if (empty($input)) {
        return $output;
    }
    
    $value = array_pop($input);
    
    return convert_array($input, [$value => $output]);
}

var_dump(convert_array($input));

It is possible without recursion: https://3v4l.org/4FuZ4

<?php

$input = ['dir2', 'dir2_1', 'dir2_1_1'];

$output = [];
foreach (array_reverse($input) as $value) {
    $output = [$value => $output];
}

var_dump($output);