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run code in 300+ PHP versions simultaneously
<?php $memory = memory_get_usage(true); print $memory ."\n"; $keys = array(); for ($i = 0; $i<1000; $i++) { $keys[] = 'pref:keyname:' . rand(1000000, 9999999); } asort($keys); print memory_get_usage(true) - $memory;

preferences:
31.19 ms | 402 KiB | 5 Q