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run code in 300+ PHP versions simultaneously
<?php $a = range(1,100000); echo memory_get_usage(), "\n"; foreach ($a as $i => $v) { if (!$i){ echo memory_get_usage(), "\n"; $a[$i] = 111; echo memory_get_usage(), "\n"; } } echo memory_get_usage(), "\n";

preferences:
36.57 ms | 402 KiB | 5 Q