<?php
// your code goes here
"Файл 1",
"Файл 2",
"Файл 3"),
"Файл 10",
"Файл 11",
"Файл 12"),
"Файл 20",
"Файл 21",
"Файл 22",
);
function walk_tree($tree, $de)
{
$result = '';
foreach ($tree as $key =>$value)
{
$result .= $de . "[{$key}]" . PHP_EOL;
$result .= walk_tree($value, $de . '___');
}
else
{
$result .= $de . $value . PHP_EOL;
}
return $result;
}
echo walk_tree($folders, '');
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