There is an array associated with each other ( id = parent_id ).

parent_id specifies the id parent.

 <?php $arr = [ [ 'id' => 1, 'parent_id' => 0, 'sysname' => 'AAA' ], [ 'id' => 2, 'parent_id' => 0, 'sysname' => 'BBB' ], [ 'id' => 3, 'parent_id' => 1, 'sysname' => 'AAA1' ], [ 'id' => 4, 'parent_id' => 3, 'sysname' => 'AAA11' ], [ 'id' => 5, 'parent_id' => 2, 'sysname' => 'BBB1' ] ]; function CreateTree( $array,$sub=0, $tab='' ) { $category=array(); if( $sub > 0 ) { $tab .= '-'; } foreach( $array as $v ) { if( $sub == $v['parent_id']) { $category[$v['id']]['id'] = $v['id']; $category[$v['id']]['parent_id'] = $v['parent_id']; $category[$v['id']]['sysname'] = $tab.$v['sysname']; $category += CreateTree($array, $v['id'], $tab); } } return $category; }

The CreateTree function Draws a tree.

The following function reverses this tree array_reverse So that deduced parents starting with it along the hierarchy

  function getNavParentsByNavId( $navTree, $id ) { $trees = array_reverse( $navTree ); $newArr = []; foreach( $trees as $tree ) { if( $tree['id'] == $id ) { $newArr[$tree['id']] = $tree['sysname']; while($current = current($trees)) { $next = next($trees); if($current['parent_id'] == $next['id']) { $newArr[$next['id']] = $next['sysname']; } } } next($trees); } return $newArr; } $navTree = CreateTree($arr); echo '<pre>'; print_r($navTree); print_r(getNavParentsByNavId($navTree, 4));

The getNavParentsByNavId function should output the part where id is equal to the passed value and after it has parents for it.

That is, the result should look like

 AAA11 AAA1 AAA

But something does not work.

    1 answer 1

     <?php $arr = [ [ 'id' => 1, 'parent_id' => 0, 'sysname' => 'AAA' ], [ 'id' => 2, 'parent_id' => 0, 'sysname' => 'BBB' ], [ 'id' => 3, 'parent_id' => 1, 'sysname' => 'AAA1' ], [ 'id' => 4, 'parent_id' => 3, 'sysname' => 'AAA11' ], [ 'id' => 5, 'parent_id' => 2, 'sysname' => 'BBB1' ] ]; function CreateTree( $array,$sub=0, $tab='' ) { $category=array(); if( $sub > 0 ) { $tab .= '-'; } foreach( $array as $v ) { if( $sub == $v['parent_id']) { $category[$v['id']]['id'] = $v['id']; $category[$v['id']]['parent_id'] = $v['parent_id']; $category[$v['id']]['sysname'] = $tab.$v['sysname']; $category += CreateTree($array, $v['id'], $tab); } } return $category; } function get_key($arr, $id) { foreach ($arr as $key => $val) { if ($val['id'] === $id) { return $key; } } return null; } function getParentsById($arr, $id, $response=[]) { $key = get_key($arr, $id); $response[] = $arr[$key]; if ($arr[$key]['parent_id'] != 0) { $response = getParentsById($arr, $arr[$key]['parent_id'], $response); } return $response; } $navTree = CreateTree($arr); print_r($navTree); print_r(getParentsById($navTree, 4));

    Example

    If only the names:

     function getParentsById($arr, $id, $response=[]) { $key = get_key($arr, $id); $response[] = $arr[$key]['sysname']; if ($arr[$key]['parent_id'] != 0) { $response = getParentsById($arr, $arr[$key]['parent_id'], $response); } return $response; }

    Example

    Well, just for the initial array you can call

     getParentsById($arr, 4)
    • get_key Fatal error: Call to undefined function get_key () - user216109
    • Well, maybe you should add the get_key function I wrote in the example? - Bookin
    • Sorry I did not notice :) - user216109