如果特定值包含在多维数组的子级别中，则返回顶级数组的键

Question

I want to return the first-level key of a multidimensional array based on the value of one of the sub-levels.

For example if I provide '@google.com' as 'Admin Emails' I want to return 'Google'.

My array is below.

$array = array (
    'Google' => array (
            'Allowed Emails' => array ('@google.com','@gmail.com' ),
            'Admin Emails' => '[e-mail], [e-mail]', // This really is supposed to be a String, not an array
            'Company Name'  => 'Alphabet',
            'Memberships' => array ('websites', 'google' ),
),
    'Facebook' => array (
            'Allowed Emails' => array ('@facebook.com','@facebook.co.uk' ),
            'Admin Emails' => '[e-mail], [e-mail]', 
            'Company Name'  => 'Facebook Limited',
            'Memberships' => array ('websites', 'facebook' ),
),
    'Apple' => array (
            'Allowed Emails' => array ('@apple.com','@icloud.com' ),
            'Admin Emails' => '[e-mail]', 
            'Company Name'  => 'Apple Inc',
            'Memberships' => array ('computers', 'apple' ),
),
        'Dell2' => array (
            'Allowed Emails' => array ('@dell.com' ),
            'Admin Emails' => '[e-mail]',
            'Company Name'  => 'Dell Computers',
            'Memberships' => array ('computers', 'dell' ),
)
);

I've managed to get a long way using array_filter but the below only works if the variable I've set (in this case 'google.com') is the first variable in the array.

Any thoughts much appreciated.

function setitem ($item){ return $item['Allowed Emails'][0] === '@google.com' ;}

$filteredarray = array_filter($array, setitem);


$toplevelarray = array_keys($filteredarray);

echo $toplevelarray[0];

Also I need some help passing the variable (in this case '@google.com' into the 'setitem' function as this won't be hard coded in. For some reason, I get an error if I try and do it the normal way.

Thanks in advance.

Answer 1

Nothing particular to do that:

$result = []; 
foreach ($array as $k => $v) {
    if ( in_array('@google.com', $v['Allowed Emails']) )
        $result[] = $k; 
}

print_r($result);

If you already know that the key is unique use a string in place of an array for $result and use break to stop the loop.

You can do the same with array_filter or array_reduce but it's slower.

To pass a variable to a function, nothing magic one more time: add a parameter.