PHP针对二维数组无限遍历变形研究

一、需要变形的二维数组

 $arr = Array(
      Array
         (
             'material_id' => 1,
             'material_name' => '铜板纸',
             'parent_id' => 0
         ),
     Array
         (
             'material_id' => 26,
             'material_name' => '哑粉纸',
             'parent_id' => 0
         ),
     Array
         (
             'material_id' => 61,
             'material_name' => '胶版',
             'parent_id' => 0
         ),
     Array
         (
             'material_id' => 95,
             'material_name' => '高级哑粉',
             'parent_id' => 0
         ),
      Array
         (
             'material_id' => 4,
             'material_name' => '250g铜版纸',
             'parent_id' => 1
         ),
      Array
         (
             'material_id' => 5,
             'material_name' => '200g铜版纸',
             'parent_id' => 1
         ),
     Array
         (
             'material_id' => 27,
             'material_name' => '250g哑粉纸',
             'parent_id' => 26
         ),

     Array
         (
             'material_id' => 28,
             'material_name' => '200g哑粉纸',
             'parent_id' => 26
         ),
     Array
     (
             'material_id' => 29,
             'material_name' => '200g哑粉纸的子项',
             'parent_id' => 28
     ),
     Array
     (
             'material_id' => 30,
             'material_name' => '200g哑粉纸的子项的子项',
             'parent_id' => 29
     )
 );

二、变形后的数组形式

 array (
   0 =>
   array (
     'material_id' => 1,
     'material_name' => '铜板纸',
     'parent_id' => 0,
     'children' =>
     array (
       0 =>
       array (
         'material_id' => 4,
         'material_name' => '250g铜版纸',
         'parent_id' => 1,
       ),
       1 =>
       array (
         'material_id' => 5,
         'material_name' => '200g铜版纸',
         'parent_id' => 1,
       ),
     ),
   ),
   1 =>
   array (
     'material_id' => 26,
     'material_name' => '哑粉纸',
     'parent_id' => 0,
     'children' =>
     array (
       0 =>
       array (
         'material_id' => 27,
         'material_name' => '250g哑粉纸',
         'parent_id' => 26,
       ),
       1 =>
       array (
         'material_id' => 28,
         'material_name' => '200g哑粉纸',
         'parent_id' => 26,
         'children' =>
         array (
           0 =>
           array (
             'material_id' => 29,
             'material_name' => '200g哑粉纸的子项',
             'parent_id' => 28,
             'children' =>
             array (
               0 =>
               array (
                 'material_id' => 30,
                 'material_name' => '200g哑粉纸的子项的子项',
                 'parent_id' => 29,
               ),
             ),
           ),
         ),
       ),
     ),
   ),
   2 =>
   array (
     'material_id' => 61,
     'material_name' => '胶版',
     'parent_id' => 0,
   ),
   3 =>
   array (
     'material_id' => 95,
     'material_name' => '高级哑粉',
     'parent_id' => 0,
   ),
 )

 三、实现代码

     public function ceshi($arr, &$arrParent = [])
     {
         // 首次获取parent_id = 0的相关父级项
         foreach ($arr as $key => $val) {
             if ($val['parent_id'] == 0) {
                 $arrParent[] = $val;
                 unset($arr[$key]);
             }
         }

         foreach ($arrParent as $parentKey => $parent) {
             foreach ($arr as $key => $val) {
                 if ($val['parent_id'] == $parent['material_id']) {
                     $arrParent[$parentKey]['children'][] = $val;
                     unset($arr[$key]); // 匹配完成则删除
                     $this->ceshi($arr, $arrParent[$parentKey]['children']);
                 }
             }
         }

         return $arrParent;
     }