Online PHP editor | output for NvLB8

@ 2017-08-23T08:33:22Z

<?php
$array = Array
(
    0 => Array
    (
        'date' => '2017-08-22',
        'AAA' => '1231',
    ),
    1 => Array
    (
        'date' => '2017-08-21',
        'AAA' => '1172',
    ),
    2 => Array
    (
        'date' => '2017-08-20',
        'AAA' => '1125'
    ),
    3 => Array
    (
        'date' => '2017-08-21',
        'BBB' => '251'
    ),
    4 => Array
    (
        'date' => '2017-08-20',
        'BBB' => '21773',
    ),
    5 => Array
    (
        'date' => '2017-08-22',
        'CCC' => '3750'
    ),
    6 => Array
    (
        'date' => '2017-08-20',
        'CCC' => '321750'
    )
);
echo '<pre>';
$array1 = array('AAA' => null, 'BBB' => null, 'CCC' => null);
$array2 = array();

array_walk($array, function ($v) use (&$array2, $array1) {
    $a = $v['date'];
    if (!isset($array2[$a])) {
        $array2[$a] = $array1;
    }
    unset($v['date']);
    $array2[$a] = array_merge($array2[$a], $v);
});

print_r($array2);

Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.4, 8.3.6: <pre>Array ( [2017-08-22] => Array ( [AAA] => 1231 [BBB] => [CCC] => 3750 ) [2017-08-21] => Array ( [AAA] => 1172 [BBB] => 251 [CCC] => ) [2017-08-20] => Array ( [AAA] => 1125 [BBB] => 21773 [CCC] => 321750 ) )
Output for 8.3.5: Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0 <pre>Array ( [2017-08-22] => Array ( [AAA] => 1231 [BBB] => [CCC] => 3750 ) [2017-08-21] => Array ( [AAA] => 1172 [BBB] => 251 [CCC] => ) [2017-08-20] => Array ( [AAA] => 1125 [BBB] => 21773 [CCC] => 321750 ) )

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