如何从多维PHP数组中检索子集？

下面是一个PHP数组：

$arr = [
    'target_a' => [],
    'target_b' => [],
    'target_c' => [
        'target_d' => [],
        'target_e' => [
            'target_f' => []
        ],
    ],
    'target_g' => [],
];

目标a，目标b，目标永远不会相互重复

我需要一个函数：superFind（），它可以执行以下操作：

superFind('target_e');
// supposed to return:
'target_e' => [
    'target_f' => []
],

superFind('target_a');
// supposed to return:
[]

即，对于给定的

target_x

值，返回一个子集（最好包括其自身）

---

我尝试过递归函数，但不知道如何解决此问题。

这应该可以为您解决此问题：

$arr = [
    'target_a' => [],
    'target_b' => [],
    'target_c' => [
        'target_d' => [],
        'target_e' => [
            'target_f' => []
        ],
    ],
    'target_g' => [],
];

function superFind($arr, $target) {
    foreach ($arr as $key => $value) {
        if ($key == $target) return $value;
        if (is_array($value)) {
            if (($found = superFind($value, $target)) !== false) return $found;
        }
    }
    return false;
}

foreach (['target_e', 'target_a', 'target_q'] as $test) {
    echo "$test: ";
    if (($found = superFind($arr, $test)) !== false) print_r($found);
    else echo "Not found";
    echo "\n";
}

输出：

target_e: Array
(
    [target_f] => Array
        (
        )

)

target_a: Array
(
)

target_q: Not found