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<?php $a = array(1,5,16,7,4); asort($a); var_dump($a); $a = array_keys($a); var_dump($a); array_walk($a, function(&$value) { ++$value; }); var_dump($a);
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.38, 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 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
array(5) { [0]=> int(1) [4]=> int(4) [1]=> int(5) [3]=> int(7) [2]=> int(16) } array(5) { [0]=> int(0) [1]=> int(4) [2]=> int(1) [3]=> int(3) [4]=> int(2) } array(5) { [0]=> int(1) [1]=> int(5) [2]=> int(2) [3]=> int(4) [4]=> int(3) }

preferences:
228.58 ms | 404 KiB | 322 Q