Read files in directory into array.

directory tree.php

<?php

/**
 * Get files in directory.
 *
 * @link https://www.php.net/manual/en/class.recursivedirectoryiterator.php#111142 Source
 *
 * @param string $dir Directory path
 *
 * @throws UnexpectedValueException
 *
 * @return array
 */
function dirTree($dir)
{
    $rdi = new \RecursiveDirectoryIterator($dir);

    // $rii = new \RecursiveIteratorIterator($rdi);

    $rii = new \RecursiveIteratorIterator($rdi, \RecursiveIteratorIterator::CHILD_FIRST);

    $tree = [];

    foreach ($rii as $splFileInfo) {
        $fileName = $splFileInfo->getFilename();

        // Skip hidden files and directories.
        if ($fileName[0] === '.') {
            continue;
        }

        $path = $splFileInfo->isDir() 
            ? array($fileName => []) 
            : array($fileName);

        for ($depth = $rii->getDepth() - 1; $depth >= 0; $depth--) {
            $path = array($rii->getSubIterator($depth)->current()->getFilename() => $path);
        }

        $tree = array_merge_recursive($tree, $path);
    }

    return $tree;
}

$dir = "C:\\xampp\\htdocs\\sample-project\\storage";

$tree = dirTree($dir);

echo json_encode($tree);