php中的递归，数组中的层次结构，打印树

Question

我有一个像这样的树形数组，带有parent-> child结构：

Array
(
    [0] => Array
        (
            [id] => 12
            [address] => root addr           
            [parent_id] => 0
            [children] => Array
                (
                    [0] => Array
                        (
                            [id] => 11
                            [address] => child addr                  
                            [parent_id] => 12
                            [children] => Array
                                (
                                    [0] => Array
                                        (
                                            [id] => 16
                                            [address] => child addr 2
                                            [parent_id] => 11
                                            [children] => Array
                                                (
                                                    [0] => Array
                                                        (
                                                            [id] => 19
                                                            [address] => child addr 3 
                                                            [parent_id] => 16
                                                        )

                                                )

                                        )

                                    [1] => Array
                                        (
                                            [id] => 18
                                            [address] => child addr 4
                                            [parent_id] => 11
                                        )

                                    [2] => Array
                                        (
                                            [id] => 20
                                            [address] => child addr 5
                                            [parent_id] => 11
                                        )

                                )

                        )

                )

        )

    [1] => Array
        (
            [id] => 17
            [address] => root addr 2        
            [parent_id] => 0
        ) 

)

我有一个构建树函数，可以打印我的树结构：

function printTree($data, $level = 0, $p_counter = 1) {    

            foreach ($data as $item) {  

                if ($item['parent_id'] == 0) {
                    $addr =  $p_counter . '. ' . $item['address'];
                    $p_counter++;
                }

                else if ($item['parent_id'] != 0) {

                    $addr =  str_repeat(' - ', $level) . $item['address'];   


                } else {
                     $addr = $item['address'];              
                }

                global $result;

                $result['aaData'][] = Array(
                 $addr,

             );   

                if (isset($item['children'])) {                    
                    printTree($item['children'], $level + 1, $p_counter + 1);
                }


            }

            return $result;        
        }

现在我的输出是这样的，带有儿童水平

1. root addr  
- child addr        
- - child arr 2 
- - - child arr 3        
- - child addr 4     
- - child addr 5     
2. root addr 2

我的目标是打印这样的数组，需要帮助！

1. root addr  
1-1. child addr        
1-1-1. child arr 2 
1-1-1-1. child arr 3        
1-1-2. child addr 4     
1-1-3. child addr 5     
2. root addr 2 

Answer 1

如果您使用

foreach ($data as $key => $item) {  

}

您可以使用$ key在字符串中获取0、1和2。