3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = array(1,2,3); foreach($a as $i => $v) { echo "$v\n"; $a[$i] = $v * 2; } var_dump($a);
Output for 5.5.0 - 5.5.38, 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.34, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.31, 8.2.0 - 8.2.27, 8.3.0 - 8.3.15, 8.4.1 - 8.4.2
1 2 3 array(3) { [0]=> int(2) [1]=> int(4) [2]=> int(6) }
preferences:
130.45 ms | 408 KiB | 5 Q