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;
    }