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run code in 300+ PHP versions simultaneously
<?php $arrays = [ [0 => 12, 5 => 10, 19 => 48], [0 => 14, 7 => 9, 12 => 11, 19 => 30], // ... more arrays ]; $result = []; foreach (array_replace(...$arrays) as $key => $_) { foreach ($arrays as $arr) { $result[$key][] = $arr[$key] ?? null; } } ksort($result); var_export($result);

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27.57 ms | 406 KiB | 5 Q