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@ 2023-02-22T03:30:18Z

<?php

$myarray = [
    [
        'messageId' => '5ACE9D8841',
        'sender' => 'john@doe.com'
    ],
    [
        'messageId' => '7EE67D8170',
        'sender' => 'dan@doe.com'
    ],
    [
        'messageId' => '8095FD8836',
        'sender' => 'cat@doe.com'
    ],
    [
        'messageId' => '7EE67D8170',
        'dest' => 'mitch@doe.com',
        'status' => 'sent',
        'date' => '2021-02-01 11:06:55'
    ]
];

var_export(
    array_reduce(
        $myarray,
        function($result, $row) {
            static $ref;
            if (!isset($ref[$row['messageId']])) {
                $ref[$row['messageId']] = $row;
                $result[] = &$ref[$row['messageId']];
            } else {
                $ref[$row['messageId']] += $row;
            }
            return $result;
        }
    )
);

Output for 8.0.1 - 8.0.30, 8.1.0 - 8.1.33, 8.2.0 - 8.2.29, 8.3.0 - 8.3.27, 8.4.1 - 8.4.14: array ( 0 => array ( 'messageId' => '5ACE9D8841', 'sender' => 'john@doe.com', ), 1 => array ( 'messageId' => '7EE67D8170', 'sender' => 'dan@doe.com', 'dest' => 'mitch@doe.com', 'status' => 'sent', 'date' => '2021-02-01 11:06:55', ), 2 => array ( 'messageId' => '8095FD8836', 'sender' => 'cat@doe.com', ), )

preferences:dark modelive previewkey bindings

91.04 ms | 407 KiB | 5 Q