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run code in 300+ PHP versions simultaneously
<?php $array =Array ( 869 => 87, 938 => 89, 870 => 127, 871 => 127, 940 => 127, 942 => 123, 947 => 123, 949 => 75 ); $return = array(); foreach ($array as $key => $value) $return[$value][] = $key; var_dump(array_values($return));
Output for 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 - 7.2.34, 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]=> array(1) { [0]=> int(869) } [1]=> array(1) { [0]=> int(938) } [2]=> array(3) { [0]=> int(870) [1]=> int(871) [2]=> int(940) } [3]=> array(2) { [0]=> int(942) [1]=> int(947) } [4]=> array(1) { [0]=> int(949) } }

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253.28 ms | 405 KiB | 414 Q