PHP遍历函数将单个数组转换为具有子元素的嵌套数组 - 基于父标识

Question

我有一个类似于这样的数组:

Array
(
    Array
    (
        [ID] => 1
        [parentcat_ID] => 0
    ),
    Array
    (
        [ID] => 2
        [parentcat_ID] => 0
    ),
    Array
    (
        [ID] => 6
        [parentcat_ID] => 1
    ),
    Array
    (
        [ID] => 7
        [parentcat_ID] => 1
    ),
    Array
    (
        [ID] => 8
        [parentcat_ID] => 6
    ),
    Array
    (
        [ID] => 9
        [parentcat_ID] => 1
    ),
    Array
    (
        [ID] => 13
        [parentcat_ID] => 7
    ),
    Array
    (
        [ID] => 14
        [parentcat_ID] => 8
    )

)

但是我需要一个函数来递归地将每个项放入相关父数组中的'children'数组中.所以它看起来更像是这样的:

Array
(
    Array
    (
        [ID] => 1
        [parentcat_ID] => 0
        [children] => Array (
            Array
            (
                [ID] => 6
                [parentcat_ID] => 1
                [childen] => Array (
                    Array
                    (
                        [ID] => 8
                        [parentcat_ID] => 6
                        [children] => Array (
                             Array
                             (
                                 [ID] => 14
                                 [parentcat_ID] => 8
                             )
                        )
                    )
                )
            ),
            Array
            (
                [ID] => 7
                [parentcat_ID] => 1
                [children] => Array(
                     Array
                     (
                         [ID] => 13
                         [parentcat_ID] => 7
                     )
                ) 
            ),
            Array
            (
                [ID] => 9
                [parentcat_ID] => 1
            )

        )
    )
    Array
    (
        [ID] => 2
        [parentcat_ID] => 0

    )

)

我希望这是有道理的!

Answer 1

给它一个去(在PHP 5.2下测试):

$inArray = array(
    array('ID' => '1', 'parentcat_ID' => '0'),
    array('ID' => '2', 'parentcat_ID' => '0'),
    array('ID' => '6', 'parentcat_ID' => '1'),  
    array('ID' => '7', 'parentcat_ID' => '1'),
    array('ID' => '8', 'parentcat_ID' => '6'),          
    array('ID' => '9', 'parentcat_ID' => '1'),  
    array('ID' => '13', 'parentcat_ID' => '7'),
    array('ID' => '14', 'parentcat_ID' => '8'),     
);

function makeParentChildRelations(&$inArray, &$outArray, $currentParentId = 0) {
    if(!is_array($inArray)) {
        return;
    }

    if(!is_array($outArray)) {
        return;
    }

    foreach($inArray as $key => $tuple) {
        if($tuple['parentcat_ID'] == $currentParentId) {
            $tuple['children'] = array();
            makeParentChildRelations($inArray, $tuple['children'], $tuple['ID']);
            $outArray[] = $tuple;   
        }
    }
}

$outArray = array();
makeParentChildRelations($inArray, $outArray);

print_r($outArray);