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<?php $array = array('title1','title2','title2','title3','title4','title5','title5','title6','title6','title5'); sort($array); $unique_length = count( array_unique($array) ); $total_dupes = 0; $clean = array(); for ($i=0; $i<$unique_length; $i++) { $current = array_shift($array); if ($current === NULL)//already have all elements break; $found = 1; while (($key = array_search($current, $array)) !== FALSE) {//search for dupes $found++; unset($array[$key]); } if ($found == 1) array_push($clean, $current); else { $dupes = array(); for ($i=0; $i<$found; $i++) $dupes[] = $current; $total_dupes++; $clean['dupe'.$total_dupes] = $dupes; } } print_r($clean);
Output for 4.3.0 - 4.3.11, 4.4.0 - 4.4.9, 5.0.0 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17, 5.3.0 - 5.3.29, 5.4.0 - 5.4.45, 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.27, 8.2.0 - 8.2.17, 8.3.0 - 8.3.4
Array ( [0] => title1 [dupe1] => Array ( [0] => title2 [1] => title2 ) [1] => title3 [2] => title4 [dupe2] => Array ( [0] => title5 [1] => title5 [2] => title5 ) [dupe3] => Array ( [0] => title6 [1] => title6 ) )

preferences:
314.86 ms | 406 KiB | 456 Q