如何通过循环动态多维数组为特定键生成数组路径？

Question

我有一个动态多维数组如下：

$cityList = [
  'AUS' => [
    'VIC' => [
      'population' => [ 'total' => '5M']
      'Richmond' => [
        'population' => [ 'total' => '0.15M']
      ]
    ],
    'NSW' => [
      'Carlton' => [
         'population' => [ 'total' => '8M']
      ]
    ]
  ]
];

此处，列人口可能存在也可能不存在于所有维度上。但是，如果它存在，那么它将始终具有 total 作为上面的子数组。

现在，我需要遍历数组并生成所有到 population 的路径（如果存在的话）。

我写的代码如下：

public function fetchAllPopulation(array $cityList, $path = '', &$cityWithPopulation)
    {
        foreach ($cityList as $key => $city) {
            if (is_array($city) && $key != 'population') {
                $path .= $path == '' ? $key: "##$key";
                $this->fetchAllPopulation($city, $path, $cityWithPopulation);
            } else {
                $population = $city['total'];
                $cityWithPopulation[$path] = $population;
            }
        }
        return $assetWithPathsAndIds;
    }

预期输出：

[
 'AUS##VIC' => '5M',
 'AUS##VIC##Richmond' => '0.15M',
 'AUS##NSW##Carlton' => '8M'
]

实际输出：

[
 'AUS##VIC' => '5M',
 'AUS##VIC##Richmond' => '0.15M',
 'AUS##VIC##NSW##Carlton' => '8M' // this is incorrect
]

问题是如果任何列的维度超过 2，那么前一个键将附加到下一个键，如上所示。

对我的代码的任何反馈或更正将不胜感激。谢谢！

Answer 1

这样：

public function fetchAllPopulation(array $cityList, $path, &$cityWithPopulation)
    {
        foreach ($cityList as $key => $city) {
            if (is_array($city) && $key != 'population') {
                $subPath = $path . ($path == '' ? $key: "##$key");
                $this->fetchAllPopulation($city, $subPath, $cityWithPopulation);
            } else {
                $population = $city['total'];
                $cityWithPopulation[$path] = $population;
            }
        }
        return $assetWithPathsAndIds;
    }

如何通过循环动态多维数组为特定键生成数组路径？

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