Where two id matching, erase the value in two arrays

I have two arrays like this :

$data = [
    0 => ['id' => 123, 'value' => 'Text'],
    1 => ['id' => 124, 'value' => 12]
];
$data2 = [
    "custom" => [
        0 => ['id' => 123, 'name' => 'Custom1', 'value' => null],
        1 => ['id' => 124, 'name' => 'Custom2', 'value' => null]
    ]
];

I would like to put the value in $data in the value of $data2 instead of "null" values where the ID are matching.

How can I do this ?

I try to do this but does not work :

foreach ($data2['custom'] as $d) {
    foreach ($data as $cf) {
        if ($cf['id'] == $d['id']):
            $cf['value'] = $d['value'];
        endif;
    }
}

Thanks

>Solution :

Here is a suggestion, first transform the $data array into an array with the id as a key to make the following process simple.

Then process over the $data2 array and in the foreach us the & reference indicator, so that amendments inside the foreach loop are applied to the original $data2 array and not the copy of the $data2 array that would normally be created as part of a foreach loop

$data = [   ['id' => 123, 'value' => 'Text'],['id' => 124, 'value' => 12] ];
$data2 = [ "custom" => [   
            ['id' => 123, 'name' => 'Custom1', 'value' => null],
            ['id' => 124, 'name' => 'Custom2', 'value' => null]]    
];

// transform $data into an array with a useful key
foreach( $data as $d){
    $useful[$d['id']] = $d['value'];
}

foreach ( $data2['custom'] as &$data ) {
    // first check that the id exists in the new useful array
    if ( isset($useful[$data['id']]) ) {
        // if it does apply the value to  the data2 array
        $data['value'] = $useful[$data['id']];
    }
}
    
print_r($data2);

RESULT

Array
(
    [custom] => Array
        (
            [0] => Array
                (
                    [id] => 123
                    [name] => Custom1
                    [value] => Text
                )
            [1] => Array
                (
                    [id] => 124
                    [name] => Custom2
                    [value] => 12
                )
        )
)

In reply to your comment about doing it without using the reference in the loop, yes like this

foreach ( $data2['custom'] as $idx => $data ) {
    if ( isset($useful[$data['id']]) ) {
        $data2['custom'][$idx]['value'] = $useful[$data['id']];
    }
}