PHP多维数组合并：如何将国家与首都子数组合并为结构化数组

Absolutely! You can achieve the desired structure by pairing elements from the country and capital arrays by their index, then building the new countries subarray. Here's how to do it:

Step-by-Step Code Example #

First, let's define your original array for clarity:

$arr = [
    'country' => ['France', 'Canada'],
    'capital' => ['Paris', 'Ottawa'],
    'other' => 'value'
];

Now, transform it to the desired format:

$result = [];

// Build the countries array by pairing country and capital elements
$result['countries'] = [];
foreach ($arr['country'] as $index => $countryName) {
    $result['countries'][] = [
        'country' => $countryName,
        'capital' => $arr['capital'][$index]
    ];
}

// Preserve the 'other' key from the original array
$result['other'] = $arr['other'];

Output #

Running this code will give you exactly the structure you want:

Array (
    [countries] => Array (
        [0] => Array ( [country] => France [capital] => Paris )
        [1] => Array ( [country] => Canada [capital] => Ottawa )
    )
    [other] => value
)

Why Your Original Code Didn't Work #

Your initial approach using array_merge() combines arrays by their keys (or numeric indices, which get reindexed), so merging ['France', 'Canada'] and ['Paris', 'Ottawa'] would just create a single flat array like ['France', 'Canada', 'Paris', 'Ottawa']—not the paired associative arrays you need. Instead, we iterate over each index to explicitly pair each country with its corresponding capital.

Note #

This solution assumes the country and capital arrays are the same length. If there's a chance they might not be, you could add a check (like isset($arr['capital'][$index])) to avoid undefined index errors.

内容的提问来源于stack exchange，提问作者Thomas