php - 使用递归来累积行而不依赖于类属性变量

Question

有这个数组:

[
    "id" => 5,
    "name" => "Item 5",
    "all_parents" => [
        "id" => 4,
        "name" => "Item 4",
        "all_parents" => [
            "id" => 3,
            "name" => "Item 3",
            "all_parents" => [
                "id" => 2,
                "name" => "Item 2",
                "all_parents" => [
                    "id" => 1,
                    "name" => "Item 1",
                    "all_parents" => null
                ]
            ]
        ]
    ]
]

我创建了一个递归 php 函数，将该数组转换为:

[
    ["id" => 1, "name" => "Item 1"],
    ["id" => 2, "name" => "Item 2"],
    ["id" => 3, "name" => "Item 3"],
    ["id" => 4, "name" => "Item 4"],
    ["id" => 5, "name" => "Item 5"],
]

代码是这样的:

private array $breadcrumb = [];
private function generateBreadcrumb($structure) : array
{
  if($structure) {
        $this->breadcrumb[] = array(
            "id" => $structure['id'],
            "name" => $structure['name'],
        );
        $this->generateBreadcrumb($structure['all_parents'] ?? []);
  }
  
  return array_reverse($this->breadcrumb);
}

如何在不依赖类属性 $breadcrumb 的情况下重新设计此方法？

Answer 1

按照您的初始代码，您可以:

function generateBreadcrumb($structure, &$output = []) : array
{
    if ($structure) {
        $output[] = array(
            "id" => $structure['id'],
            "name" => $structure['name'],
        );
        $this->generateBreadcrumb($structure['all_parents'] ?? [], $output);
    }

    return array_reverse($output);
}

但是它可以改进，至少避免每次都调用 array_reverse()，但仅限于根调用。