Question

我有这个方法，它将采用单维数组并将其转换为多维数组。它是一个类别的邻接列表。我随时都会注入一个枚举路径。它有90％的时间有效。

public function fnExpandArray($aData){

    $aNested = array();

    foreach($aData as &$aCat){

        if(isset($aData[$aCat['parent_id']])){

            $aData[$aCat['parent_id']]['sub'][$aCat['id']] = &$aCat;
            $aData[$aCat['parent_id']]['sub'][$aCat['id']]['path'] = $aData[$aCat['parent_id']]['path'] . '_' . $aCat['id'];

        } else {

            $aNested[$aCat['id']] = &$aCat;
            $aNested[$aCat['id']]['path'] = $aCat['id'];

        }

    }

    unset($aCat);
    return $aNested;
}

这种方法在90％的情况下正常工作，但是＆＃34;路径＆＃34;正在注入的索引有时会在之后注入＆＃34; sub＆＃34;索引并导致枚举路径计算不正确。示例：

正确：

[18] => Array ( [id] => 18 [parent_id] => 1 [title] => Category 1 [path] => 1_18 [sub] => Array ( [150] => Array ( [id] => 150 [parent_id] => 18 [title] => Category 2 [path] => 1_18_150

但是在一些迭代中，它会注入“路径”。在＆＃39; sub＆＃39;之后而且例程将失败。

失败：

[45] => Array ( [id] => 45 [parent_id] => 2 [sub] => Array ( [10] => Array ( [id] => 10 [parent_id] => 45 [sub] => Array ( [152] => Array ( [id] => 152 [parent_id] => 10 [title] => Category 1 [path] => _152 ) [79] => Array ( [id] => 79 [parent_id] => 10 [title] => Category 2 [path] => _10_79 ) ) [title] => Dryers [path] => _10

注意子注入后如何注入路径和标题。知道为什么吗？

Answer 1

此方法重写解决了我的问题。在阵列上多次传球。

public function fnExpandTaxonomy(&$aData) {

    $aTree = array();

    // Loop original flat array, build associative and inject additional indices as required. 
    foreach($aData as $iKey => &$aCat){
        $aTree[$aCat['id']] = &$aCat;
        $aTree[$aCat['id']]['level'] = 0; 
        $aTree[$aCat['id']]['path'] = $aCat['id']; 
        $aTree[$aCat['id']]['sub'] = array(); 
    }

    // Loop - Add children to parents. 
    foreach($aTree as $iKey => &$aCat) {
        if(!$aCat['parent_id']) continue;

        unset($aCat['level'],$aCat['path'],$aCat['sub']);
        $aCat['level'] = $aTree[$aCat['parent_id']]['level']+1; 
        $aCat['path'] = $aTree[$aCat['parent_id']]['path'].'_'.$aCat['id']; 
        $aTree[$aCat['parent_id']]['sub'][$aCat['id']] = &$aCat;

    }

    // Loop again, remove any items that don't have a parent of 0;
    foreach($aTree as $iKey => &$aCat) {
      if(!$aCat['parent_id']) continue;
      unset($aTree[$iKey]);
    }

    unset($aCat);
    return $aTree;  

}

非常感谢pyson，他在另一个类似线程中的答案（下图）帮助了我。

create array tree from array list

PHP foreach在一些迭代中不按顺序注入新索引

1 个答案: