3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array(1,2,3); $b = &$a; foreach($a as $i => $v) { echo "$v\n"; $a[2] = 'qqq'; unset($a[1]); } var_dump($a); var_dump($b);
Output for 7.0.0 - 7.0.31, 7.1.0 - 7.1.25, 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 2 3 array(2) { [0]=> int(1) [2]=> string(3) "qqq" } array(2) { [0]=> int(1) [2]=> string(3) "qqq" }
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.38
1 qqq array(2) { [0]=> int(1) [2]=> string(3) "qqq" } array(2) { [0]=> int(1) [2]=> string(3) "qqq" }
preferences:
237.59 ms | 402 KiB | 291 Q