元のarray_diffと同じように機能するより優れた関数。
array1を1つ以上の他の配列と比較し、他のどの配列にも再帰的に存在しないarray1の値を返します。
    <?php
    function md_array_diff(array $array1, array $array2, array $_ = null) {
        $diff = [];
        $args = array_slice(func_get_args(), 1);
        foreach ($array1 as $key => $value) {
            foreach ($args as $item) {
                if (is_array($item)) {
                    if (array_key_exists($key, $item)) {
                        if (is_array($value) && is_array($item[$key])) {
                            $tmpDiff = md_array_diff($value, $item[$key]);
                            if (!empty($tmpDiff)) {
                                foreach ($tmpDiff as $tmpKey => $tmpValue) {
                                    if (isset($item[$key][$tmpKey])) {
                                        if (is_array($value[$tmpKey]) && is_array($item[$key][$tmpKey])) {
                                            $newDiff = array_diff($value[$tmpKey], $item[$key][$tmpKey]);
                                        } else if ($value[$tmpKey] !== $item[$key][$tmpKey]) {
                                            $newDiff = $value[$tmpKey];
                                        }
                                        if (isset($newDiff)) {
                                            $diff[$key][$tmpKey] = $newDiff;
                                        }
                                    } else {
                                        $diff[$key][$tmpKey] = $tmpDiff;
                                    }
                                }
                            }
                        } else if ($value !== $item[$key]) {
                            $diff[$key] = $value;
                        }
                    } else {
                        $diff[$key] = $value;
                    }
                }
            }
        }
        return $diff;
    }
    $arr1 = [
      "A" => [
        "A1" => ['A1-0', 'A1-1', 'A1-2', 'A1-3'],
        "A2" => ['A2-0', 'A2-1', 'A2-2', 'A2-3'],
        "A3" => ['A3-0', 'A3-1', 'A3-2', 'A3-3']
      ],
      "B" => [
        "B1" => ['B1-0', 'B1-1', 'B1-2', 'B1-3'],
        "B2" => ['B2-0', 'B2-1', 'B2-2', 'B2-3'],
        "B3" => ['B3-0', 'B3-1', 'B3-2', 'B3-3']
      ],
      'C' => 123
    ];
    $arr2 = [
      "A" => [
        "A1" => ['A1-1', 'A1-2', 'A1-3'],
        "A2" => ['A2-0', 'A2-1', 'A2-2', 'A2-3'],
        "A3" => ['A3-0', 'A3-1', 'A3-2']
      ],
      "B" => [
        "B1" => ['B1-0', 'B1-2', 'B1-3'],
        "B2" => ['B2-0', 'B2-1', 'B2-2', 'B2-3'],
        "B3" => ['B3-0', 'B3-1', 'B3-3']
      ]
    ];
    $arr3 = [
      "A" => [
        "A1" => ['A1-0', 'A1-1', 'A1-2', 'A1-3'],
        "A2" => ['A2-0', 'A2-1', 'A2-2', 'A2-3'],
        "A3" => ['A3-0', 'A3-1', 'A3-2']
      ],
      "B" => [
        "B1" => ['B1-0', 'B1-2', 'B1-3'],
        "B2" => ['B2-0', 'B2-1', 'B2-2', 'B2-3'],
        "B3" => ['B3-0', 'B3-1', 'B3-3']
      ]
    ];
    $diff = md_array_diff($arr1, $arr2, $arr3);
    ?>
    Will Output:
    array (size=3)
      'A' =>
          array (size=2)
            'A1' =>
              array (size=1)
                0 => string 'A1-0' (length=4)
            'A3' =>
              array (size=1)
                3 => string 'A3-3' (length=4)
      'B' =>
          array (size=2)
            'B1' =>
              array (size=1)
                1 => string 'B1-1' (length=4)
            'B3' =>
              array (size=1)
                2 => string 'B3-2' (length=4)
      'C' => int 123