3v4l.org

run code in 300+ PHP versions simultaneously
<?php $array = array("100_1", "100_2", "100_3", "101_1", "102_1", "102_2", "103_1", "103_2", "103_3", "104_1", "104_2"); sort($array); foreach($array as $value) { $parts = explode('_', $value); $result[$parts[0]] = $value; } $result = array_values($result); print_r($result);
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 - 5.6.28, 7.0.0 - 7.0.20, 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Array ( [0] => 100_3 [1] => 101_1 [2] => 102_2 [3] => 103_3 [4] => 104_2 )
preferences:
305.45 ms | 406 KiB | 384 Q