Online PHP editor | refs for rjqOh

<?php $array = [ [ ["2011-11-18 00:00:00" => 'C'], ["2011-11-18 00:00:00" => 'I'], ["2011-11-18 00:00:00" => 'S'], ], [ ["2011-11-22 00:00:00" => 'C'], ["2011-11-22 00:00:00" => 'S'] ] ]; $result = []; foreach ($array as $set) { foreach ($set as $row) { foreach ($row as $k => $_) { $result[$k] = ($result[$k] ?? 0) + 1; } } } var_export($result);