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<?php $a = &$b; $b = 1; echo $a; echo "\n---\n"; $c = &$d[0]; $d[0] = 1; var_dump($c, $d); $d = [2]; var_dump($c, $d);
Output for 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
1 --- int(1) array(1) { [0]=> &int(1) } int(1) array(1) { [0]=> int(2) }

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172.95 ms | 403 KiB | 212 Q