3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = [ [0 => 1, 1 => 5, 3 => null], [0 => 4, 1 => null, 3 => null], [0 => null, 1 => 5, 3 => 5] ]; $result = []; foreach ($array as $row) { foreach ($row as $k => $v) { $result[$k] = ($result[$k] ?? 0) + ($v !== null); } } var_export($result);

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23.43 ms | 404 KiB | 5 Q