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<?php $array = [ [ 'id' => 1, 'title' => 'dir 1', 'parent_id' => 0, ], [ 'id' => 2, 'title' => 'dir 2', 'parent_id' => 0, ], [ 'id' => 3, 'title' => 'dir 3', 'parent_id' => 2, ], [ 'id' => 4, 'title' => 'dir 4', 'parent_id' => 3, ], [ 'id' => 5, 'title' => 'dir 5', 'parent_id' => 6, ], [ 'id' => 6, 'title' => 'dir 6', 'parent_id' => 0, ], ]; function build_tree($array, $parent_id = 0) { $result = []; foreach ($array as $item) { if ($item['parent_id'] == $parent_id) { $new_item = $item; $new_item['children'] = build_tree($array, $new_item['id']); $result[] = $new_item; } } return $result; } $tree = build_tree($array); print_r($tree);
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6
Array ( [0] => Array ( [id] => 1 [title] => dir 1 [parent_id] => 0 [children] => Array ( ) ) [1] => Array ( [id] => 2 [title] => dir 2 [parent_id] => 0 [children] => Array ( [0] => Array ( [id] => 3 [title] => dir 3 [parent_id] => 2 [children] => Array ( [0] => Array ( [id] => 4 [title] => dir 4 [parent_id] => 3 [children] => Array ( ) ) ) ) ) ) [2] => Array ( [id] => 6 [title] => dir 6 [parent_id] => 0 [children] => Array ( [0] => Array ( [id] => 5 [title] => dir 5 [parent_id] => 6 [children] => Array ( ) ) ) ) )
Output for 8.3.5
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0 Array ( [0] => Array ( [id] => 1 [title] => dir 1 [parent_id] => 0 [children] => Array ( ) ) [1] => Array ( [id] => 2 [title] => dir 2 [parent_id] => 0 [children] => Array ( [0] => Array ( [id] => 3 [title] => dir 3 [parent_id] => 2 [children] => Array ( [0] => Array ( [id] => 4 [title] => dir 4 [parent_id] => 3 [children] => Array ( ) ) ) ) ) ) [2] => Array ( [id] => 6 [title] => dir 6 [parent_id] => 0 [children] => Array ( [0] => Array ( [id] => 5 [title] => dir 5 [parent_id] => 6 [children] => Array ( ) ) ) ) )

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