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<?php $myarray = ["2011-06-21", "2011-06-22", "2011-06-22", "2011-06-23", "2011-06-23", "2011-06-24", "2011-06-24", "2011-06-25", "2011-06-25", "2011-06-26"]; $result = []; foreach ($myarray as $k => $v) { $result[$v][] = $k; } var_export(array_filter($result, 'array_key_last'));
Output for 7.4.0 - 7.4.33, 8.0.1 - 8.0.30, 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 ( '2011-06-22' => array ( 0 => 1, 1 => 2, ), '2011-06-23' => array ( 0 => 3, 1 => 4, ), '2011-06-24' => array ( 0 => 5, 1 => 6, ), '2011-06-25' => array ( 0 => 7, 1 => 8, ), )
preferences:
92.91 ms | 1297 KiB | 3 Q