CODEWITHSUNDEEP
phparraysmultidimensional-arrayfilter
Forza
Forza

Reputation: 1649

Find the column value of the first item in a multidimensional array with a sought value in a deep subarray

I am creating a contact form, which needs to change the sendto address based on an entered postal code.

I have an array of postal codes which I can search through, so that I know if the postal code entered is actually in the array.

Here's how I search through the array:

$districts = [
    'district' => [
        [
            'name' => 'District A',
            'email' => '[email protected]',
            'url' => 'district-a',
            'postalcodes' => [
                '3311AA',
                '3311AB',
            ],
        ],
        [
            'name' => 'District B',
            'email' => '[email protected]',
            'url' => 'district-b',
            'postalcodes' => [
                '3317EA',
                '3317EB',
                '3317EC',
            ],
        ],
    ],
];

$results = array_filter($districts['district'], function($district) {
    $key = array_search('3311AB', $district['postalcodes']);
    return $key;
});

var_dump($results);

Now I need to return the email address, based on in which district the postal code is found.

How would I search for, for example, postal code 3311AB and return the email address of the district to which it belongs?

Upvotes: 2

Views: 71

Answers (2)

mickmackusa
mickmackusa

Reputation: 47764

From PHP8.4, you can enjoy functional style programming with the efficiency boost of short-circuiting internal loops by nesting array_any() calls inside of an array_find() call. Demo

$find = '3311AB';
echo array_find(
         $districts['district'],
         fn($d) => array_any(
             $d['postalcodes'],
             fn($pc) => $pc === $find
         )
     )['email'] ?? 'Not found';
// [email protected]

If limited by your PHP version or if a functional style script is not desired, a manual loop with a conditionally break performs the same way. I am implementing array destructuring syntax in the head of the loop to access only the relevant column values. Demo

$found = null;
$find = '3311AB';
foreach ($districts['district'] as ['email' => $e, 'postalcodes' => $pc]) {
    if (in_array($find, $pc)) {
        $found = $e;
        break;
    }
}
echo $found ?? 'Not found';
// [email protected]

Upvotes: 0

Justinas
Justinas

Reputation: 43441

Instead of returning key of postal code, you need to return $district['email']

$emails = [];

foreach ($districts['district'] as $district) {
    if (in_array('3311AB', $district['postalcodes'])) {
        $emails[] = $district['email'];
    }
}

var_dump($emails);

Example

Upvotes: 6

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