Online PHP editor | refs for bvNKI

<?php $array = []; for ($i = 0, $j = 100; $i < $j; ++$i) { $array[] = new DateTimeImmutable(); } function a($array) { $fn = function () use ($array) { foreach ($array as $item) { $x = $item instanceof DateTimeImmutable; } }; return $fn; } function b($array) { $fn = function () use (&$array) { foreach ($array as $item) { $x = $item instanceof DateTimeImmutable; } }; return $fn; } $t1 = microtime(true); for ($i = 0; $i < 100; ++$i) { a($array); } $t2 = microtime(true); for ($i = 0; $i < 100; ++$i) { b($array); } $t3 = microtime(true); echo (1000000 * ($t2 - $t1)) . "\n\n"; echo (1000000 * ($t3 - $t2)) . "\n\n";