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run code in 300+ PHP versions simultaneously
<?php function uuid($c = 4) { $x = function($c) { for ($n = ''; strlen($n) < $c + 1; $n = $n.mt_rand()); return substr($n, -$c); }; return sprintf( '%s-%04d-%04d-%04d-%04d%04d', microtime(true) * 1000, $x($c), $x($c), $x($c), $x($c), $x($c), $x($c) ); } $time = microtime(); $uuids = array(); for ($i = 0; $i < 10000; $i++) { $uuids[] = uuid(); } if (count(array_unique($uuids)) != count($uuids)) { echo 'DUPLICATE'; } else { echo 'No duplicate'; print_r($uuids); }

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