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<?php $array = [ ["2" => 6, "5" => 1], ["2" => 1, "5" => 3], ]; $result = []; foreach ($array as $row) { foreach ($row as $k => $v) { if (!isset($result[$k]) || $result[$k] < $v){ $result[$k] = $v; } } } var_export($result);
Output for 8.1.0 - 8.1.34, 8.2.0 - 8.2.30, 8.3.0 - 8.3.30, 8.4.1 - 8.4.18, 8.5.0 - 8.5.3
array ( 2 => 6, 5 => 3, )

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